Possible role of lncRNAs in amelioration of Parkinson's disease symptoms by transplantation of dopaminergic cells

Long non-coding RNAs (lncRNAs) are biomarkers for diagnosis and treatment of Parkinson's disease (PD). Since dopaminergic cell transplantation is a clinical method to treat PD, this study investigated the effects of dopaminergic cell therapy on the expression of some lncRNAs and genes related to PD. In this study, Twenty-eight rats were randomly assigned to four experimental groups. The control group (Sal group) received saline injections. The Par group was a PD rat model with 6-hydroxydopamine (6-OHDA) injection in right striatum (ST). PD animals were transplanted by undifferentiated P19 stem cells (Par-E group), and P19-derived dopaminergic cells (Par-N group). Cell transplant effects were evaluated using behavioral tests (cylinder, open field, and rotarod tests), and histological methods (H&E and Nissl staining, and immunohistochemistry). Moreover, the expression of lncRNAs MALAT1, MEG3, and SNHG1, alongside specific neuronal (synaptophysin) and dopaminergic (tyrosine hydroxylase) markers was evaluated by qRT-PCR. Behavioral and histopathological examinations revealed that cell transplantation partially compensated dopaminergic cell degeneration in ST and substantia nigra (SN) of PD rats. The expression of MALAT1, SNHG1, and MEG3 was decreased in the ST of the Par group, while MEG3 and SNHG1 gene expression was increased in PBMC relative to the Sal group. In PBMC of the Par-N group, all three lncRNAs showed a reduction in their expression. Conversely, MALAT1 and SNHG1 expression was increased in ST tissue, while MEG3 gene expression was decreased compared to the Sal group. In conclusion, dopaminergic cell transplantation could change the lncRNAs expression. Furthermore, it partially improves symptoms in PD rats.

Multimodality Dosimetric Evaluation for the Treatment of Recurrent Brain Tumors

PURPOSE/OBJECTIVE(S)

GammaTile Surgically Targeted Radiation Therapy (STaRT) are bioresorbable collagen tiles containing four Cesium-131 radioactive seeds which are permanently implanted into the operative bed immediately following the surgical resection of a brain tumor. Alternative radiation treatment approaches for recurrent brain tumors include external beam radiation therapy (EBRT) with either proton or photon (volumetric modulated arc therapy, or VMAT) radiation. The purpose of this study is to perform a comparative dosimetric study of these three modalities for cases of recurrent brain tumors. We hypothesize that GammaTile would be dosimetrically superior at sparing radiation dose to surrounding organs at risk.

MATERIALS/METHODS

A total of 5 patients have received GammaTile StaRT therapy at our institute for recurrent brain tumors in 2021-2022. Out of these 5 patients, 3 were recurrent glioblastoma (GBM) and 2 were brain metastasis (brain-met) cases. All patients were previously treated with radiation. Typical prescription for GammaTile therapy is 60 Gy to the High Risk CTV (HR_CTV), specified by 5mm depth from the plane of the seeds. For recurrent GBM cases, the alternative methods of radiation are proton therapy and photon therapy using VMAT. The standard re-irradiation dose for proton and photon therapy is 35 Gy in 10 fractions prescribed to PTV (3 mm expansion of EBRT CTV). For brain-met cases, an alternate method is hypo-fractionation radiation therapy with Linac-based SBRT. Linac-based SBRT prescription depends on the volume of EBRT CTV. For one of the brain-met cases, the SBRT prescription was 30 Gy in 5 fractions, and for the other case it was 27 Gy in 3 fractions to PTV (2 mm expansion from EBRT CTV). Proton and photon plans were generated in a treatment planning system using a double scattering Mevion system and a VersaHD with agility head, respectively. All the physical doses were converted to biological effective dose (BED) for evaluation.

RESULTS

The dosimetric quantities are summarized in table 1. These quantities were evaluated using HR_CTV and EBRT_CTV for GammaTile therapy and EBRT (proton/photon), respectively. GammaTile therapy reduces dose to normal brain tissue considerably. However, it may have more uncertainty in the dose delivered compared to proton and photon EBRT.

CONCLUSION

It appears that all three treatment modalities are adequate for treating recurrent brain tumors. However, GammaTile therapy may allow to deliver higher dose to the targets while reducing the irradiation to adjacent normal tissue.

Evaluation of 68Ga-Fibroblast Activation Protein Inhibitor vs. 18F-FDG as a Novel Radiotracer for Biologically Guided Radiation Therapy

PURPOSE/OBJECTIVE(S)

Real-time biology guided radiation therapy (BgRT) uses real-time positron emissions from a PET tracer during treatment to guide targeted radiation to cancerous lesions. Fibroblast activation protein alpha (FAP) is highly expressed on cancer-associated fibroblasts in tumors with low expression in normal tissues. While 18F-FDG-PET requires fasting and has background in the liver and brain, 68-Gallium labeled FAP inhibitor (FAPI) does not require fasting and has less background uptake. The goal of this study was to investigate the utility of FAPI as a potential universal fiducial for BgRT. We hypothesized that 68Ga-FAPI would be a better radiotracer than 18F-FDG, as assessed by the Normalized Minimal kBq/mL and the Normal Target Signal (NTS), two parameters used to gauge the suitability of BgRT.

MATERIALS/METHODS

PET-CTs were obtained for 50 patients with pancreatic, liver, lung, head & neck, and cervical cancer using 18F-FDG and 68Ga-FAPI (n = 10 for each). Four DICOM images were obtained per patient (FDG PET + CT, FAPI PET + CT). Radiation oncologists delineated the gross tumor volume (GTV) on PET images. A separate set of auto-contours were generated from the PET using an auto-threshold of 40% maximum SUV for all tumors. A 1 cm expansion was added to the GTV to create a ring around the physician-generated contours and auto-contours. The following parameters were measured: GTV volume, SUV max of GTV, SUV mean of GTV, Normalized Minimal kBq/mL within the GTV, and NTS (= SUV max/Ring SUV mean). Values were compared using paired t-test. For the BgRT product with similar calculations, the required Normalized Minimal kBq/mL is > 5 kBq/mL; the required NTS is > 2.7 for treatment planning and > 2.0 for BgRT delivery.

RESULTS

The Normalized Minimal kBq/mL for FAPI was > 5 kBq/mL for all tumors and greater for auto-contoured GTVs compared to physician-contoured GTVs. The mean NTS for the auto-contours for all tumor sites was > 2.0. In addition, there was a statistically significant increase in the NTS for FAPI compared to FDG in pancreatic, liver and head & neck cancers. In pancreatic cancer, there was a statistically significant increase in Normalized Minimal kBq/mL for FAPI compared to FDG (26.0 vs 14.2) (p = 0.01) and the SUVmax of FAPI was almost double that of FDG (15.9 vs 8.2) (p = 0.01). FAPI had no background in the liver, but had high background in the uterus, suggesting it may have a role in liver cancer but not cervical cancer.

CONCLUSION

This is the first study demonstrating the potential superiority of 68Ga-FAPI compared to 18F-FDG as a biologic fiducial for BgRT when treating pancreatic, liver and head & neck cancers, with a similar efficacy for lung cancer. Our results indicate that auto-contoured GTVs generate a higher NTS than physician-contoured GTVs but all are > 2.0. In addition, the Normalized Minimal kBq/mL for auto-contours is > 5 kBq/mL for all tumors. As hypothesized, FAPI-based BgRT is most likely to be successful when treating tumors with significant desmoplastic stroma, such as pancreatic cancer.

Long-Term Quality of Life Following Head and Neck Radiation: A Study Using the Vanderbilt Head and Neck Symptom Survey

PURPOSE/OBJECTIVE(S)

Head and neck (H&N) radiation (RT) is characterized by significant acute toxicity, but long-term quality of life (QoL) following H&N RT is not well defined. This study sought to prospectively characterize, by subsite, long-term QoL in patients who underwent H&N RT using the Vanderbilt Head and Neck Symptom Survey (VHNSS) version 2.0.

MATERIALS/METHODS

In patients treated with H&N RT between 2010 and 2021, the VHNSS was prospectively collected prior to beginning RT and at follow-up visits after completion of RT. Responses were broken down into symptom clusters for characterization of specific side effects and scored from 0 (asymptomatic) to 10 (severe symptoms). Patients were stratified by disease site and type of RT, with three main subgroups of interest: p16+ oropharynx (OPX) treated with definitive RT, nasopharynx (NPX) treated with definitive RT, and oral cavity (OC) treated with postoperative RT (PORT). To characterize long-term QoL, surveys collected 2 years (±3 months) after completion of RT were analyzed. Survey response distributions are reported as median and interquartile ranges. Comparisons between groups were made using the Mann-Whitney U test.

RESULTS

A total of 65 patients (33 OPX [50.8%], 19 NPX [29.2%], 13 OC [20.0%]) had survey responses at 2 years. Median age was 56 (range 20-86). 48 (73.8%) patients were male. Concurrent chemotherapy was administered to 52 patients (80.0%). At 2 years, among OPX patients, trouble hearing (1.5 [0-5]) represented the greatest symptom burden, though this was still less than NPX (4.0 [2.0-7.5]; p = 0.099) patients but greater than OC (0.0 [0.0-1.5]; p = 0.16) patients. OPX patients had significantly less difficulty swallowing solids (0.8 [0.1-2.0]) compared to NPX (2.5 [1.1-5.1]; p = 0.018) and OC (3.5 [1.9-5.1]; p = 0.002) patients. OPX patients also experienced less dry mouth (1.0 [0.2-3.3]) than NPX (3.2 [1.5-6.6]; p = 0.012) and OC (2.4 [1.8-5.4]; p = 0.056) patients. OPX patients reported less trismus (0.0 [0.0-0.2]) than NPX (4.0 [0.0-7.0]; p<0.001) and OC (1.0 [0.5-3]; p = 0.002) patients. OPX patients had less neck tightness (0.0 [0.0-2.0]) than NPX (2.0 [0.0-3.0]; p = 0.022) patients and less voice dysfunction (0.0 [0.0-0.7]) than OC (3.0 [1.2-3.5]; p = 0.011) patients. Lastly, OPX patients had better mental health (0.0 [0.0-1.2]) than NPX (2.0 [0.0-5.0]; p = 0.019) and OC (2.0 [0.0-3.2]; p = 0.086) patients. There was no difference in taste/smell among OPX (0.9 [0.0-2.7]), NPX (2.3 [0.7-5.1]; p = 0.100), and OC (1.5 [1.1-3.4]; p = 0.230) patients.

CONCLUSION

The VHNSS was able to characterize long-term QoL in patients treated with H&N RT. In general, patients with OPX treated with definitive RT have improved long-term QoL relative to patients with NPX or OC cancers, though at least a quarter of patients still report significant dry mouth, taste/smell, and hearing difficulties. Additional work should seek to identify, and, where possible through timely rehabilitation, proactively mitigate late symptoms in patients following H&N RT.

Patient and Caregivers Opinions on Receiving Radiology Results before Oncologist Appointments

PURPOSE/OBJECTIVE(S)

With the passing of the Cures Act, patients now have immediate access to radiology reports and can review the results before discussing the findings with a physician. In Oncology, the results of these imaging reports can be especially sensitive as the results can lead to difficult discussions about patient prognosis, or the need for invasive medical, surgical, or radiation therapies. It is unclear whether immediate access may increase anxiety, stress, and confusion before discussions with an oncologist. In this study, we hypothesized that in the oncology setting, immediate access to imaging reports before meeting with their oncologist would be associated with worsened patient anxiety.

MATERIALS/METHODS

Patients and their caregivers were invited to complete an investigator-developed anonymous multiple-choice survey prior to a scheduled follow-up appointment with their radiation oncologist. Survey questions assessed preferences for reviewing the radiology report prior to their oncology visit, their reported level of anxiety before undergoing diagnostic imaging, after directly receiving their results, and after they have the discussion of their results with the oncologist. Additional metrics collected included patient demographics, the time interval between discussing the results with an oncologist, preference for reviewing the images or just the radiology report, satisfaction with having immediate access to the report, and if they would prefer being blinded from the results until after discussing with their oncologist. Survey items were scored descriptively through summary statistics.

RESULTS

In this interim report of 54 individuals surveyed over a two-week period (89% were patients, 11% were caregivers/family members), a combined 33% reported a high level of anxiety before undergoing their scan. Levels of high anxiety decreased to 20% for those who received their report prior to reviewing with their oncologist and further lowered to 13% after reviewing the report and images with their oncologist. 57% of responders reported discussing the results with an oncologist within 2 days of receiving results. 46% preferred reviewing only radiology reports and not the images, 35% favored reviewing both imaging and the report together and 19% had no preference. Only 18.5% of responders preferred viewing the reports before discussing them with their oncologist and only 20% felt it was beneficial having early access to them.

CONCLUSION

Anxiety associated with oncology-related imaging improved after immediate access to the report and after discussions with oncologists. A small proportion of patients preferred having early access to imaging reports and most patients preferred reviewing only the report, not the images. Strategies including shortened intervals between immediate access and discussions with oncologists may minimize anxiety associated with imaging as most patients preferred first discussing the results with their oncologist.

Omission of Adjuvant Radiotherapy in Low-Risk Elderly Males with Breast Cancer

PURPOSE/OBJECTIVE(S)

Randomized clinical trials demonstrate that lumpectomy + hormone therapy (HT) without radiation therapy (RT) yields equivalent survival and acceptable local-regional outcomes in elderly women with early-stage, node-negative (T1-2N0) hormone-receptor positive (HR+) breast cancer. Whether these data apply to men with the same inclusion criteria remains unknown. We hypothesized that outcomes in males would be comparable to those seen in females, with RT not conferring an overall survival (OS) benefit over HT alone.

MATERIALS/METHODS

We conducted a retrospective matched-cohort study using the National Cancer Database for males ≥65 years with pathologic T1-2N0 (≤3 cm) HR+ breast cancer treated with breast conserving surgery with negative margins from 2004-2019. Patients who received chemotherapy, had nodal or distant metastases, or unknown follow-up were excluded. Adjuvant treatment was classified as HT alone, RT alone, or HT+RT. Due to limitations of survival analysis on retrospective data, male patients were matched with female patients to determine comparable outcomes based on age (± 3 years), Charlson Deyo comorbidity score, T-stage, and adjuvant treatment. Survival analysis was performed using Cox regression and Kaplan-Meier analysis. To adjust for confounding, inverse probability of treatment weighting (IPTW) was used.

RESULTS

A total of 523 patients met inclusion criteria, with 24.4% receiving HT, 16.3% receiving RT, and 59.2% receiving HT+RT. Median follow-up was 6.9 years (IQR: 5.0-9.4 years). Unadjusted 5-yr OS rates in the HT, RT, and HT+RT cohorts were 79.2% (95% CI 70.7-85.5%), 80.9% (95% CI 70.3-88.0%), and 93.3% (95% CI 89.7-95.7%), respectively. Adjusted 10-yr OS rates in the HT, RT, and HT+RT cohorts were 82.3% (95% CI 78.6-85.5%), 83.6% (95% CI 80.0-86.7%), and 92.8% (95% CI 90.1-94.8%), respectively. On unadjusted multivariable Cox regression analysis (MVA), relative to HT, receipt of HT+RT was associated with improvements in OS (HR: 0.603; 95% CI: 0.410-0.888; p = 0.01). RT alone was not associated with improved OS (HR: 1.116; 95% CI: 0.710-1.755; p = 0.633). On adjusted MVA, relative to HT, receipt of HT+RT was associated with improvements in OS (HR: 0.551; 95% CI: 0.370-0.820; p = 0.003). Again, RT alone was not associated with improved OS (HR: 0.991; 95% CI: 0.613-1.604; p = 0.972). Other factors associated with OS included age, Charlson Deyo score, T stage, and grade. Overall, in the matched women, the same trends were found as in the men, the best survival was in HT+RT, but no difference in OS between HT vs. RT.

CONCLUSION

Among men ≥65 years old with T1-2N0 HR+ breast cancer, RT alone did not confer an OS benefit over HT alone. Combined RT+HT did yield improvements in OS, though there are likely significant unmeasured confounders contributing to these outcomes in patients treated with the most aggressive approach. Our findings support that RT omission may be a reasonable option in elderly men with T1-2N0 HR+ breast cancer treated with lumpectomy + HT.

Incidence of Major Depression, Suicidal Ideation, and Mental Health Treatment Amongst Cancer Survivors

PURPOSE/OBJECTIVE(S)

Receiving a cancer diagnosis and undergoing subsequent treatments can result in a significant psychological burden for cancer patients. However, there is conflicting literature on the incidence of major depression in cancer patients compared to patients without cancer. The purpose of this study was to investigate and further clarify the incidence of major depression, associated treatments, and suicidal ideation in cancer survivors compared to a non-cancer cohort.

MATERIALS/METHODS

This is a retrospective, population-based study using survey responses from the National Survey on Drug Use and Health collected from January 2015 to December 2019. Survey data sets were queried for all respondents aged 18 years or older who provided a cancer history. Patients with a reported history of cancer ("cancer survivors") were further stratified by whether they reported a "recent" cancer diagnosis within the past 12 months. Survey responses were then evaluated for recent diagnoses of and treatments for major depressive disorder and suicidal ideation. Rates were compared between cancer survivors and participants without cancer using the Pearson χ2 test and multivariable logistic regression models, respectively.

RESULTS

Among the 212,411 survey respondents identified, 7,635 (3.6%) reported a cancer history, with 1,486 (0.7%) reporting a recent cancer history. The incidence of major depression was not different between cancer survivors and participants without cancer (9.3% vs. 9.2%; p = 0.762), though the incidence was slightly higher amongst recent cancer survivors (10.0% vs. 9.2%; p = 0.259). Among patients diagnosed with major depression, cancer survivors were significantly more likely to receive treatment for depression (78.6% vs. 60.3%, p<0.001), with 72.6% discussing depressive symptoms with a medical professional and 64.3% receiving prescription medication. Suicidal ideation was significantly lower among cancer survivors (5.1% vs. 6.2%, p<0.001) including recent survivors (5.0% vs. 6.2%, p<0.001). Suicidal ideation was higher in patients with underlying major depression in both cancer survivors and participants without cancer (30.6% vs. 35.6%, p = 0.015). On logistic regression, respondents with underlying depression receiving treatment were more likely to have suicidal ideation (OR: 1.49; p<0.001) while having a cancer diagnosis did not correlate with suicidal ideation (OR: 0.87; p = 0.869).

CONCLUSION

There was no significant overall difference in the incidences of major depression between cancer survivors and patients without cancer. However, one consideration is the under-diagnosis depression among cancer survivors. Symptoms of depression may be overlooked and mistakenly attributed to appropriate grief from a cancer diagnosis. Among patients diagnosed with major depression, cancer survivors were more likely to receive treatment for depression. These results highlight the importance of early depression assessment and treatment for cancer survivors.

Prognostic Significance of Positron Emission Tomography Delta Radiomics Following Bridging Therapy in Patients with Large B-Cell Lymphoma Undergoing CAR T-Cell Therapy

PURPOSE/OBJECTIVE(S)

CAR T-cell therapy is routinely used as a treatment option for relapsed/refractory large B-cell lymphoma (LBCL). Bridging therapy radiation therapy (bRT) is increasingly being utilized prior to chimeric antigen receptor (CAR) T-cell therapy for large B-cell lymphoma (LBCL). It is unknown how the extent of debulking as a result of bRT impacts outcomes following CAR T-cell infusion. We hypothesized that the extent of debulking is prognostic of overall response to therapy.

MATERIALS/METHODS

We reviewed patients with LBCL treated with bRT followed by commercially available CAR T-cell therapy between 2017 and 2022. Patients required a F-fluorodeoxyglucose (FDG) positron emission tomography (PET) scan prior to bRT and between completion of bRT and CAR T-cell infusion. On each scan, metabolic tumor volume (MTV), maximum standardized uptake value (SUVmax), SUVmean, and total lesion glycolysis (TLG) were determined. Delta-radiomics based on changes of these values between scans in patients overall and irradiated sites were then calculated. Optimal cut points were determined using maximally selected log-rank. The primary endpoints were progression-free survival (PFS) and local control (LC), measured from CAR T-cell infusion by Kaplan-Meier and Fine-Gray competing risk survival analyses, respectively.

RESULTS

Twenty-three patients with LBCL with 33 irradiated sites were reviewed. All metabolically active disease was treated in 10 patients. Median equivalent dose in 2 Gy fractions (EQD2) was 26 Gy (14-44). Median interval from bRT to PET was 9 days (2-30). Following bRT, 2 patients achieved complete responses, 16 had partial responses, and 5 had progressive disease. Five irradiated sites progressed through bRT. No local failures were observed when EQD2>32.5 Gy was given. LC was improved with EQD2>20 Gy (24 mo LC: 94.5% vs 68.6%; p = 0.075). Following BRT, median overall decreases in MTV, SUVmax, SUVmean, and TLG were 22.2 cc (63.1%), 8.9 (36.8%), 3.4 (31.1%), and 297.9 cc (75.8%), respectively. Median decreases in MTV, SUVmax, SUVmean, and TLG in irradiated sites were 15.6 cc (91.1%), 17.0 (74.6%), 6.8 (55.3%), and 157.0 cc (94.6%), respectively. PFS was significantly improved in patients with reductions of MTV of at least 36 cc (24 mo PFS: 69.2% vs 0%; p = 0.047) or SUVmax of at least 15 (24-mo PFS: 80.0% vs 28.1%; p < 0.001). LC was significantly improved in lesions with reductions of SUVmax of at least 14 (24-mo LC: 100% vs 67.3%; p < 0.001) or SUVmean of at least 7 (24-mo LC: 100% vs 74.4%; p < 0.001).

CONCLUSION

bRT led to significant reductions in MTV, SUVmax, SUVmean, and TLG. The extent of these decreases correlated with improved PFS and LC. There appears to be a dose-response relationship. Larger cohorts should validate the value of interim PET following bRT, and associated changes in disease burden as a means of prognosticating patients. Future work might evaluate whether escalation of BT in patients with suboptimal response, using either systemic therapy or higher radiation doses, has an impact on outcomes.

Machine Learning and Explainable Artificial Intelligence to Predict Occult Pelvic Nodal Metastases in Prostate Cancer

PURPOSE/OBJECTIVE(S)

Determination of risk of occult pelvic lymph node involvement (LNI) in patients with cN0 prostate cancer is critical for determination of optimal treatment options. Though several nomograms exist, machine learning (ML) approaches might enable physicians to better assess individual risk by incorporating multiple clinical risk factors. Herein, we developed a ML model to predict occult LNI, and explained its composition using an explainable artificial intelligence (XAI) framework.

MATERIALS/METHODS

Patients with cN0 prostate adenocarcinoma diagnosed from 2018-2020 were identified in the National Cancer Database. The query was limited to patients with known clinical staging and biopsy results who did not receive neoadjuvant therapy prior to pelvic nodal examination. Occult LNI was defined as pN1 disease based on surgical evaluation, with a minimum of 10 nodes examined. Five ML models were trained to predict LNI. Variables incorporated into the model were age, core biopsy results, Gleason scores, preoperative prostate specific antigen (PSA), and clinical T-stage. Model performance, measured using area under the receiver operator characteristic curve (AUC) on a holdout testing dataset, was compared to multivariable logistic regression. The best-performing model was explained using SHapley Additive exPlanation (SHAP) values. To permit more clinically-meaningful statistical interpretation, using a novel approach SHAP values were converted into odds ratios (OR), confidence intervals (CI), and p-values.

RESULTS

A total of 23,131 patients met inclusion criteria; 2,676 (11.6%) had occult LNI. The Extreme Gradient Boosting model outperformed all other models with an AUC of 0.82 (95% CI: 0.78-0.86) compared to 0.80 (95% CI: 0.76-0.84) for logistic regression. Increasing PSA (OR: 1.031; p<0.001), number of positive biopsy cores (OR: 1.055; p<0.001), and percent positive biopsy cores (OR: 1.01; p<0.001) were all associated with increased risk of LNI. Based on observation of SHAP dependence plots, risk of LNI plateaued at PSA>20 ng/dL and >11 positive cores, while no plateau was observed for percent positive biopsy cores. Relative to T1c disease, patients with T3b were at highest risk of LNI (OR: 1.461; p = 0.003). Gleason score of 9 was associated with significant risk of LNI (Ref: Gleason 6; OR: 1.891; p<0.001). This was primarily driven by the primary Gleason score; primary Gleason 5 disease was associated with significant risk of LNI (Ref: Gleason 3; OR: 1.915; p<0.001) while a secondary Gleason score of 5 was the only grade with significant increased risk of LNI (Ref: Gleason 3; OR: 1.185; p = 0.004). Age and number of cores examined were not significant predictors of LNI.

CONCLUSION

Our ML achieved improved performance relative to logistic regression at predicting occult LNI. XAI provided insight into the inner-working of the ML model. ML can be used to identify patients at risk for occult LNI and therefore inform clinical decision-making.

Patterns of Care for Patients with Locally Advanced Rectal Cancer Treated with Total Neoadjuvant Therapy between 2016-2020: An NCDB Analysis

PURPOSE/OBJECTIVE(S)

Treatment for locally advanced rectal cancer (LARC), defined as T3/4 or any T with N+ disease, typically requires multi-modality management consisting of radiation (RT), chemotherapy (CHT), and surgery. Despite emerging evidence that total neoadjuvant therapy (TNT) is the preferred treatment of LARC, it remains unknown what proportion of patients are receiving TNT in the United States. Our objective was to (1) determine the proportion of patients with LARC receiving TNT over time, (2) determine the most common method in which TNT is being delivered, and (3) determine what factors are associated with a lower likelihood of receiving TNT in the United States.

MATERIALS/METHODS

Retrospective data was obtained from the National Cancer Database (NCDB) for patients diagnosed with rectal cancer between 2016-2020. Patients were excluded if they had M1 disease, T1-2 N0 disease, incomplete staging information, non-adenocarcinoma histology, received RT to a non-rectum site, or received a non-definitive RT dose. Patients were determined to have received TNT if they (1) received RT and multi-agent (MA)-CHT prior to surgery, (2) had an interval of >180 days from the onset of neoadjuvant therapy to surgery if they received long course (LC)-chemoradiation (CRT) (based on 35 days for LC-CRT + 112 days for 8 cycles of MA-CHT + 30 days to surgery), or (3) had an interval of >150 days from the onset of neoadjuvant therapy to surgery if they received short course (SC)-RT (based on 5 days for SC-RT + 112 days for 8 cycles of MA-CHT + 30 days to surgery). Data were analyzed using linear regression, Chi-square test, and binary logistic regression.

RESULTS

Of the 26,375 patients included, the median age was 60 (range 21-90) years, with the majority of patients being <65 years old (65.6%), male (62.1%), and non-Hispanic white (77.0%). A total of 5,003 (19.0%) patients received TNT, and 21,372 (81.0%) patients received classical combined modality therapy (CMT). The proportion of patients receiving TNT increased significantly over time, from 6.1% in 2016, 9.0% in 2017, 15.3% in 2018, 25.8% in 2019, to 34.6% in 2020 (slope = 7.36, 95% CI 4.58-10.15, R2 = 0.96, p = 0.040). The most common TNT regimen was MA-CHT followed by LC-CRT (73.2% of cases from 2016-2020). The proportion of patients receiving SC-RT as part of TNT significantly increased from 2.8% in 2016, 1.7% in 2017, 4.6% in 2018, 7.3% in 2019, to 13.7% in 2020 (slope = 2.74, 95% CI 0.37-5.11, R2 = 0.82, p = 0.035). On multivariate analysis, factors associated with a lower likelihood of TNT use included age >65 (OR 0.66, 95% CI 0.61-0.71, p<0.001), female gender (OR 0.92, 95% CI 0.86-0.98, p = 0.014), Black race (OR 0.87, 95% CI 0.77-0.98, p = 0.024), and T3 N0 disease (OR 0.60, 95% CI 0.52-0.70, p<0.001).

CONCLUSION

TNT utilization rates have significantly increased in recent years, from 6.1% in 2016 to 34.6% in 2020. The observed trend appears to be in line with the recent National Comprehensive Cancer Network (NCCN) guidelines recommending TNT as the preferred approach.

Synergistic Effect of TVEC and Radiotherapy in the Treatment of Advanced Melanoma

PURPOSE/OBJECTIVE(S)

Talimogene laherparepvec (TVEC) is a genetically modified herpes simplex virus (HSV-1) that has been approved by the US Food and Drug Administration (FDA) for intralesional treatment of melanoma. Recent reports have suggested that radiation treatment (RT) given in conjunction with TVEC, may provide synergistic immune enhancement at the site, and possibly systemically. However, the studies on combining RT with TVEC remain limited. Our study compares melanoma patients (pts) who received TVEC and RT in the same region of the body with pts whose RT field did not include the site of TVEC injection. We hypothesized that RT and TVEC to the same site would induce a more robust local tumor response, and possibly a systemic response, with improvement in clinical outcomes over those pts who had treatments in different regions.

MATERIALS/METHODS

This was a retrospective review of 20 melanoma pts from a single cancer center who were treated with TVEC and RT between January 2015 and September 2022. Overall survival (OS), progression-free survival (PFS), time to distant metastasis (DM), and time to locoregional recurrence (LRR) were compared using Kaplan-Meier analysis and the corresponding log-rank test. Skin toxicity was also tabulated.

RESULTS

Fourteen pts (stage III [71.4%]; stage IV [28.6%]) received TVEC and RT in the same region (left leg [5], right leg [5], back [1], left arm [1], and right arm [1], and scalp [1]), and six (stage III [66.7%]; stage IV [33.3%]) received treatments in separate regions. The overall median follow-up was 10.5 months (mos) (range 1.0 - 58.7 mos). The OS of pts who had TVEC and RT in the same region was 19.0 mos (95% confidence interval [CI], 4.1 - not reached [NR] mos), compared to 18.5 mos for those receiving RT in a different region (95% CI, 1.0 - NR mos) (p = 0.366). PFS with TVEC and RT in the same and different regions were 6.4 mos (95% CI, 2.4 - NR mos) and 2.8 mos (95% CI, 0.7 - 4.4 mos) respectively (p = 0.005). DM was 13.8 mos (95% CI, 4.6 - NR mos) with TVEC and RT in the same field and 2.8 mos (95% CI, 0.7 - 4.4 mos) in different fields (p = 0.001). Lastly, LRR of pts who had TVEC and RT in the same region was 26.0 mos (95% CI, 6.4 - 26.0 mos) compared to 4.4 mos in different regions (95% CI, 0.7 - NR mos) (p = 0.115). No grade 3 or higher skin toxicities were documented among pts who had TVEC and RT in the same region.

CONCLUSION

Comparing pts who had TVEC and RT to different regions of the body, there was an association with improvements in PFS and DM when both modalities were delivered to the same region of the body. However, we did not find a significant difference in locoregional recurrence or OS. Given some promise with the combined approach and potential immune enhancement from RT, larger trials are needed to better understand the potential positive signal from our study.

Size-dependent molecular interaction of nontraditional 2D antibiotics withStaphylococcus aureus

The application of nanomaterials for their antibacterial properties is the subject of many studies due to antibiotic resistance of pathogen bacteria and the necessity of omitting them from food and water resources. Graphene oxide (GO) is one of the most popular candidates for antibacterial application. However, the optimum condition for such an effect is not yet clear for practical purposes. To shed light on how GO and bacteria interaction depends on size, a wide range of GO flake sizes from hundreds of µm²going down to nano-scale as low as 10 N m²was produced. In anin-vitrosystematic study to inhibitStaphylococcus aureusgrowth, the correlation between GO flake size, thickness, functional group density, and antibacterial activity was investigated. The GO suspension with the average size of 0.05 µm², in the order of the size of the bacteria itself, had the best bacteriostatic effect onS. aureuswith the minimum inhibitory concentration value of 8 μg ml^-1, well within the acceptable range for practical use. The bacteriostatic effect was measured to be a 76.2% reduction of the colony count over 2 h of incubation and the mechanism of action was the wrapping and isolation of cells from the growth environment. Furthermore,in-vivoanimal studies revealed that 16 μg ml^-1of the optimum GO has efficient antibacterial performance against the methicillin-resistant strains of the bacteria with an enhanced wound healing rate and tensiometrial parameters which is important for realized targets.

1211 An Ameloblastoma Or Intra-Oral Basal Cell Carcinoma? A Clinical Case Report

A basal cell ameloblastoma is an uncommon benign neoplasm and has a similar histological appearance to basal cell carcinoma of the skin. This clinical case report will discuss an ameloblastoma originating in the maxilla and of the baseloid variant. The objective of report is to highlight the possibility of misdiagnosis from this challenging case.

A 34-year-old male was referred to the maxillofacial department with recurrent nasal regurgitation following dental extraction from the left maxilla 1 year previous. Clinically there was an oro-antral fistula visible and initial CT showed cystic lesion in the left maxilla likely to represent an odontogenic cyst. The patient underwent extraction and enucleation, where the diagnosis of the amelobalstoma was established with need of resection. Partial maxillectomy and primary closure with buccal fadpad was performed in the second stage and histological results showed a 6mm completely excised basal cell carcinoma within the oral mucosa and no bony invasion. Due to this extremely unusual results, secondary histological review was requested, and conclusion was a fully excised basal cell ameloblastoma. Following the procedure and subsequent reviews, the patient has no evidence of oro-antral fistula or recurrence of this rare type of neoplasm.

A basal cell ameloblastoma variant is a rare lesion and due to its’ similar histological appearance to a basal cell carcinoma, can lead to a misdiagnosis. The aim of the report is to show the unusual presentation and findings along the way to correct diagnosis in this case.

1247 Fusobacterium Necrophorum - A Rare Thyroglossal Cyst Habitat That Can Be Lethal

Thyroglossal cyst is the most frequent developmental cervical anomaly with a prevalence of 7% in the population. Infection and abscess formation are common complications. Isolation of Fusobacterium Necrophorum (F. Necrophorum) made the management of this case challenging.

An 18-year-old male presented to the emergency department with a 3-day history of a neck mass, sore throat, cachexia, dysphagia and fever. Clinical examination revealed an erythematous 4 x 5 fluctuant swelling in the midline of the neck with evident lymphadenopathy on level II on the left-hand side. A CT neck that was undertaken nine months ago was suggestive of a thyroglossal cyst and the patient was placed in the waiting list for surgical excision under general anaesthesia. He reported three episodes of midline neck swelling since then.

Upon admission, ultrasound guided drainage was arranged, and a pus sample obtained. The presence of F. Necrophorum was reported by microbiology with instructions of urgent admission and strict antibiotic regime. Excision of the cyst was scheduled after the completion of the antibiotic course.

Fusobacterium Necrophorum is a rare microorganism with increased virulence and a significant mortality rate. It has been involved in oropharyngeal infections complicated by Lemierre’s syndrome, necrobacillosis, post anginal sepsis and septic jugular thrombophlebitis making this case of particular interest.

The reliability and heritability of cortical folds and their genetic correlations across hemispheres

Cortical folds help drive the parcellation of the human cortex into functionally specific regions. Variations in the length, depth, width, and surface area of these sulcal landmarks have been associated with disease, and may be genetically mediated. Before estimating the heritability of sulcal variation, the extent to which these metrics can be reliably extracted from in-vivo MRI must be established. Using four independent test-retest datasets, we found high reliability across the brain (intraclass correlation interquartile range: 0.65-0.85). Heritability estimates were derived for three family-based cohorts using variance components analysis and pooled (total N > 3000); the overall sulcal heritability pattern was correlated to that derived for a large population cohort (N > 9000) calculated using genomic complex trait analysis. Overall, sulcal width was the most heritable metric, and earlier forming sulci showed higher heritability. The inter-hemispheric genetic correlations were high, yet select sulci showed incomplete pleiotropy, suggesting hemisphere-specific genetic influences.