Comparative analysis of the tumor microbiome, molecular profiles, and immune cell abundances by HPV status in mucosal head and neck cancers and their impact on survival

Head and Neck Squamous Cell Carcinoma (HNSCC) comprises a diverse group of tumors with variable treatment response and prognosis. The tumor microenvironment (TME), which includes microbiome and immune cells, can impact outcomes. Here, we sought to relate the presence of specific microbes, gene expression, and tumor immune infiltration using tumor transcriptomics from The Cancer Genome Atlas (TCGA) and associate these with overall survival (OS). RNA sequencing (RNAseq) from HNSCC tumors in TCGA was processed through the exogenous sequences in tumors and immune cells (exotic) pipeline to identify and quantify low-abundance microbes. The detection of the Papillomaviridae family of viruses assessed HPV status. All statistical analyses were performed using R. A total of 499 RNAseq samples from TCGA were analyzed. HPV was detected in 111 samples (22%), most commonly Alphapapillomavirus 9 (90.1%). The presence of Alphapapillomavirus 9 was associated with improved OS [HR = 0.60 (95%CI: 0.40-0.89, p = .01)]. Among other microbes, Yersinia pseudotuberculosis was associated with the worst survival (HR = 3.88; p = .008), while Pseudomonas viridiflava had the best survival (HR = 0.05; p = .036). Microbial species found more abundant in HPV- tumors included several gram-negative anaerobes. HPV- tumors had a significantly higher abundance of M0 (p < .001) and M2 macrophages (p = .035), while HPV+ tumors had more T regulatory cells (p < .001) and CD8+ T-cells (p < .001). We identified microbes in HNSCC tumor samples significantly associated with survival. A greater abundance of certain anaerobic microbes was seen in HPV tumors and pro-tumorigenic macrophages. These findings suggest that TME can be used to predict patient outcomes and may help identify mechanisms of resistance to systemic therapies.

Modeling the Risk of Hearing Loss From Radiation Therapy in Childhood Cancer Survivors: A PENTEC Comprehensive Review

PURPOSE

The Pediatric Normal Tissue Effects in the Clinic (PENTEC) hearing loss (HL) task force reviewed investigations on cochlear radiation dose-response relationships and risk factors for developing HL. Evidence-based dose-response data are quantified to guide treatment planning.

METHODS AND MATERIALS

A systematic review of the literature was performed to correlate HL with cochlear dosimetry. HL was considered present if a threshold exceeded 20 dB at any frequency. Radiation dose, ototoxic chemotherapy exposure, hearing profile including frequency spectra, interval to HL, and age at radiation therapy (RT) were analyzed.

RESULTS

Literature was systematically reviewed from 1970 to 2021. This resulted in 739 abstracts; 19 met inclusion for meta-analysis, and 4 included data amenable to statistical modeling. These 4 studies included 457 cochleas at risk in patients treated with RT without chemotherapy, and 398 cochlea treated with chemotherapy. The incidence and severity of cochlear HL from RT exposure alone is related to dose and age. Risk of HL was <5% in cochlea receiving a mean dose ≤35 Gy but increased to 30% at 50 Gy. HL risk ranged from 25% to 40% in children under the age of 5 years at diagnosis, declining to 10% in older children for any radiation dose. Probability of similar severe HL occurred at doses 18.3 Gy higher for children <3 versus >3 years of age. High-frequency HL was most common, with average onset occurring 3.6 years (range, 0.4-13.2 years) after RT. Exposure to platinum-based chemotherapies added to the rates of HL at a given cochlear dose level, with 300 mg/m2 shifting the dose response by 7 Gy.

CONCLUSIONS

In children treated with RT alone, risk of HL was low for cochlear dose <35 Gy and rose when dose exceeded 35 Gy without clear RT dose dependence. High-frequency HL was most prevalent, but all frequencies were affected. Children younger than 5 years were at highest risk of developing HL, although independent effects of dose and age were not fully elucidated. Future reports with more granular data are needed to better delineate time to onset of HL and the effects of chemoradiotherapy.

Testicular Dysfunction in Male Childhood Cancer Survivors Treated With Radiation Therapy: A PENTEC Comprehensive Review

PURPOSE

The male reproductive task force of the Pediatric Normal Tissue Effects in the Clinic (PENTEC) initiative performed a comprehensive review that included a meta-analysis of publications reporting radiation dose-volume effects for risk of impaired fertility and hormonal function after radiation therapy for pediatric malignancies.

METHODS AND MATERIALS

The PENTEC task force conducted a comprehensive literature search to identify published data evaluating the effect of testicular radiation dose on reproductive complications in male childhood cancer survivors. Thirty-one studies were analyzed, of which 4 had testicular dose data to generate descriptive scatter plots. Two cohorts were identified. Cohort 1 consisted of pediatric and young adult patients with cancer who received scatter radiation therapy to the testes. Cohort 2 consisted of pediatric and young adult patients with cancer who received direct testicular radiation therapy as part of their cancer therapy. Descriptive scatter plots were used to delineate the relationship between the effect of mean testicular dose on sperm count reduction, testosterone, follicle stimulating hormone (FSH), and luteinizing hormone (LH) levels.

RESULTS

Descriptive scatter plots demonstrated a 44% to 80% risk of oligospermia when the mean testicular dose was <1 Gy, but this was recovered by >12 months in 75% to 100% of patients. At doses >1 Gy, the rate of oligospermia increased to >90% at 12 months. Testosterone levels were generally not affected when the mean testicular dose was <0.2 Gy but were abnormal in up to 25% of patients receiving between 0.2 and 12 Gy. Doses between 12 and 19 Gy may be associated with abnormal testosterone in 40% of patients, whereas doses >20 Gy to the testes were associated with a steep increase in abnormal testosterone in at least 68% of patients. FSH levels were unaffected by a mean testicular dose <0.2 Gy, whereas at doses >0.5 Gy, the risk was between 40% and 100%. LH levels were affected at doses >0.5 Gy in 33% to 75% of patients between 10 and 24 months after radiation. Although dose modeling could not be performed in cohort 2, the risk of reproductive toxicities was escalated with doses >10 Gy.

CONCLUSIONS

This PENTEC comprehensive review demonstrates important relationships between scatter or direct radiation dose on male reproductive endpoints including semen analysis and levels of FSH, LH, and testosterone.

Essential data variables for a minimum dataset for head and neck cancer trials and clinical research: HNCIG consensus recommendations and database

The Head and Neck Cancer International Group (HNCIG) has undertaken an international modified Delphi process to reach consensus on the essential data variables to be included in a minimum database for HNC research. Endorsed by 19 research organisations representing 34 countries, these recommendations provide the framework to facilitate and harmonise data collection and sharing for HNC research. These variables have also been incorporated into a ready to use downloadable HNCIG minimum database, available from the HNCIG website.

Systematic Implementation of Effective Quality Assurance Processes for the Assessment of Radiation Target Volumes in Head and Neck Cancer

PURPOSE

Significant heterogeneity exists in clinical quality assurance (QA) practices within radiation oncology departments, with most chart rounds lacking prospective peer-reviewed contour evaluation. This has the potential to significantly affect patient outcomes, particularly for head and neck cancers (HNC) given the large variance in target volume delineation. With this understanding, we incorporated a prospective systematic peer contour-review process into our workflow for all patients with HNC. This study aims to assess the effectiveness of implementing prospective peer review into practice for our National Cancer Institute Designated Cancer Center and to report factors associated with contour modifications.

METHODS AND MATERIALS

Starting in November 2020, our department adopted a systematic QA process with real-time metrics, in which contours for all patients with HNC treated with radiation therapy were prospectively peer reviewed and graded. Contours were graded with green (unnecessary), yellow (minor), or red (major) colors based on the degree of peer-recommended modifications. Contours from November 2020 through September 2021 were included for analysis.

RESULTS

Three hundred sixty contours were included. Contour grades were made up of 89.7% green, 8.9% yellow, and 1.4% red grades. Physicians with >12 months of clinical experience were less likely to have contour changes requested than those with <12 months (8.3% vs 40.9%; P < .001). Contour grades were significantly associated with physician case load, with physicians presenting more than the median number of 50 cases having significantly less modifications requested than those presenting <50 (6.7% vs 13.3%; P = .013). Physicians working with a resident or fellow were less likely to have contour changes requested than those without a trainee (5.2% vs 12.6%; P = .039). Frequency of major modification requests significantly decreased over time after adoption of prospective peer contour review, with no red grades occurring >6 months after adoption.

CONCLUSIONS

This study highlights the importance of prospective peer contour-review implementation into systematic clinical QA processes for HNC. Physician experience proved to be the highest predictor of approved contours. A growth curve was demonstrated, with major modifications declining after prospective contour review implementation. Even within a high-volume academic practice with subspecialist attendings, >10% of patients had contour changes made as a direct result of prospective peer review.

A Multicenter Evaluation of Different Chemotherapy Regimens in Older Adults With Head and Neck Squamous Cell Carcinoma Undergoing Definitive Chemoradiation

PURPOSE

The number of older adults with head and neck squamous cell carcinoma (HNSCC) is increasing, and treatment of these patients is challenging. Although cisplatin-based chemotherapy concomitantly with radiation therapy is considered the standard regimen for patients with locoregionally advanced HNSCC, there is substantial real-world heterogeneity regarding concomitant chemotherapy in older patients with HNSCC.

METHODS AND MATERIALS

The SENIOR study is an international multicenter cohort study including older patients (≥65 years) with HNSCC treated with definitive radiation therapy at 13 academic centers in the United States and Europe. Patients with concomitant chemoradiation were analyzed regarding overall survival (OS) and progression-free survival (PFS) via Kaplan-Meier analyses. Fine-Gray competing risk regressions were performed regarding the incidence of locoregional failures and distant metastases.

RESULTS

Six hundred ninety-seven patients with a median age of 71 years were included in this analysis. Single-agent cisplatin was the most common chemotherapy regimen (n = 310; 44%), followed by cisplatin plus 5-fluorouracil (n = 137; 20%), carboplatin (n = 73; 10%), and mitomycin C plus 5-fluorouracil (n = 64; 9%). Carboplatin-based regimens were associated with diminished PFS (hazard ratio [HR], 1.39 [1.03-1.89]; P < .05) and a higher incidence of locoregional failures (subdistribution HR, 1.54 [1.00-2.38]; P = .05) compared with single-agent cisplatin, whereas OS (HR, 1.15 [0.80-1.65]; P = .46) was comparable. There were no oncological differences between single-agent and multiagent cisplatin regimens (all P > .05). The median cumulative dose of cisplatin was 180 mg/m2 (IQR, 120-200 mg/m2). Cumulative cisplatin doses ≥200 mg/m2 were associated with increased OS (HR, 0.71 [0.53-0.95]; P = .02), increased PFS (HR, 0.66 [0.51-0.87]; P = .003), and lower incidence of locoregional failures (subdistribution HR, 0.50 [0.31-0.80]; P = .004). Higher cumulative cisplatin doses remained an independent prognostic variable in the multivariate regression analysis for OS (HR, 0.996 [0.993-0.999]; P = .009).

CONCLUSIONS

Single-agent cisplatin can be considered in the standard chemotherapy regimen for older patients with HNSCC who can tolerate cisplatin. Cumulative cisplatin doses are prognostically relevant in older patients with HNSCC.

Palliative Quad Shot Radiation Therapy with or without Concurrent Immune Checkpoint Inhibition for Head and Neck Cancer

OBJECTIVES

Patients with recurrent and metastatic head and neck cancer (HNC) have limited treatment options. 'QuadShot' (QS), a hypofractionated palliative radiotherapy regimen, can provide symptomatic relief and local control and may potentiate the effects of immune checkpoint inhibitors (ICIs). We compared outcomes of QS ± concurrent ICIs in the palliative treatment of HNC.

MATERIALS AND METHODS

We identified patients who received ≥three cycles of QS from 2017 to 2022 and excluded patients without post-treatment clinical evaluation or imaging. Outcomes for patients who received QS alone were compared to those treated with ICI concurrent with QS, defined as receipt of ICI within 4 weeks of QS.

RESULTS

Seventy patients were included, of whom 57% received concurrent ICI. Median age was 65.5 years (interquartile range [IQR]: 57.9-77.8), and 50% patients had received prior radiation to a median dose of 66 Gy (IQR: 60-70). Median follow-up was 8.8 months. Local control was significantly higher with concurrent ICIs (12-month: 85% vs. 63%, p = 0.038). Distant control (12-month: 56% vs. 63%, p = 0.629) and median overall survival (9.0 vs. 10.0 months, p = 0.850) were similar between the two groups. On multivariable analysis, concurrent ICI was a significant predictor of local control (HR for local failure: 0.238; 95% CI: 0.073-0.778; p = 0.018). Overall, 23% patients experienced grade 3 toxicities, which was similar between the two groups.

CONCLUSIONS

The combination of QS with concurrent ICIs was well tolerated and significantly improved local control compared to QS alone. The median OS of 9.4 months compares favorably to historical controls for patients with HNC treated with QS. This approach represents a promising treatment option for patients with HNC unsuited for curative-intent treatment and warrants prospective evaluation.

Scalp Irradiation with 3D-Milled Bolus: Initial Dosimetric and Clinical Experience

BACKGROUND AND PURPOSE

A bolus is required when treating scalp lesions with photon radiation therapy. Traditional bolus materials face several issues, including air gaps and setup difficulty due to irregular, convex scalp geometry. A 3D-milled bolus is custom-formed to match individual patient anatomy, allowing improved dose coverage and homogeneity. Here, we describe the creation process of a 3D-milled bolus and report the outcomes for patients with scalp malignancies treated with Volumetric Modulated Arc Therapy (VMAT) utilizing a 3D-milled bolus.

MATERIALS AND METHODS

Twenty-two patients treated from 2016 to 2022 using a 3D-milled bolus and VMAT were included. Histologies included squamous cell carcinoma (n = 14, 64%) and angiosarcoma (n = 8, 36%). A total of 7 (32%) patients were treated in the intact and 15 (68%) in the postoperative setting. The median prescription dose was 66.0 Gy (range: 60.0-69.96).

RESULTS

The target included the entire scalp for 8 (36%) patients; in the remaining 14 (64%), the median ratio of planning target volume to scalp volume was 35% (range: 25-90%). The median dose homogeneity index was 1.07 (range: 1.03-1.15). Six (27%) patients experienced acute grade 3 dermatitis and one (5%) patient experienced late grade 3 skin ulceration. With a median follow-up of 21.4 months (range: 4.0-75.4), the 18-month rates of locoregional control and overall survival were 75% and 79%, respectively.

CONCLUSIONS

To our knowledge, this is the first study to report the clinical outcomes for patients with scalp malignancies treated with the combination of VMAT and a 3D-milled bolus. This technique resulted in favorable clinical outcomes and an acceptable toxicity profile in comparison with historic controls and warrants further investigation in a larger prospective study.

Outcomes of definitive local therapy with intensity-modulated radiation therapy in elderly patients ≥70 years with HPV-associated oropharyngeal cancer

The incidence of human papillomavirus (HPV) associated oropharyngeal squamous cell carcinoma (OPSCC) is increasing among elderly (≥70 years) patients and the optimal treatment approach is not known. In this study, we aimed to determine disease and toxicity outcomes in an elderly HPV-OPSCC population primarily treated with a chemoradiation (CRT) approach. We identified 70 elderly HPV-OPSCC patients who were treated with either surgery, radiotherapy, or CRT between 2011 and 2021. Time-to-event analysis for overall survival (OS), progression-free survival (PFS), and local control (LC) were conducted using the Kaplan-Meier method. Univariate and multivariable cox regression models were used to estimate the hazard ratio associated with covariates. The median follow-up for our cohort was 43.9 months. Of the 70 elderly patients, 55 (78.6%) receive CRT and 15 (22.4%) received RT alone. Two patients underwent TORS resection. Of the 55 patients treated with CRT, the most common systemic agents were weekly carboplatin/taxol (n = 18), cetuximab (n = 17), and weekly cisplatin (n = 11). The 5-year OS, PFS, and LC were 57%, 52%, and 91%, respectively. On univariate analysis, Eastern Cooperative Oncology Group performance status and Charlson Comorbidity Index (CCI) were significant predictors of OS, while on multivariate analysis only CCI was a significant predictor of OS (p = 0.006). The rate of late peg tube dependency, osteoradionecrosis, and aspiration was 10%, 4%, and 4%, respectively. Definitive local therapy in elderly HPV-OPSCC patients is associated with excellent LC and a low rate of late toxicities. Prospective studies are needed to further stratify subgroups of elderly patients who may benefit from aggressive definitive local therapy.

Factors Associated with Total Laryngectomy Utilization in Patients with cT4a Laryngeal Cancer

BACKGROUND

Despite recommendations for upfront total laryngectomy (TL), many patients with cT4a laryngeal cancer (LC) instead undergo definitive chemoradiation, which is associated with inferior survival. Sociodemographic and oncologic characteristics associated with TL utilization in this population are understudied.

METHODS

This retrospective cohort study utilized hospital registry data from the National Cancer Database to analyze patients diagnosed with cT4a LC from 2004 to 2017. Patients were stratified by receipt of TL, and patient and facility characteristics were compared between the two groups. Logistic regression analyses and Cox proportional hazards methodology were performed to determine variables associated with receipt of TL and with overall survival (OS), respectively. OS was estimated using the Kaplan-Meier method and compared between treatment groups using log-rank testing. TL usage over time was assessed.

RESULTS

There were 11,149 patients identified. TL utilization increased from 36% in 2004 to 55% in 2017. Treatment at an academic/research program (OR 3.06) or integrated network cancer program (OR 1.50), male sex (OR 1.19), and Medicaid insurance (OR 1.31) were associated with increased likelihood of undergoing TL on multivariate analysis (MVA), whereas age > 61 (OR 0.81), Charlson-Deyo comorbidity score ≥ 3 (OR 0.74), and clinically positive regional nodes (OR 0.78 [cN1], OR 0.67 [cN2], OR 0.21 [cN3]) were associated with decreased likelihood. Those undergoing TL with post-operative radiotherapy (+/- chemotherapy) had better survival than those receiving chemoradiation (median OS 121 vs. 97 months; p = 0.003), and TL + PORT was associated with lower risk of death compared to chemoradiation on MVA (HR 0.72; p = 0.024).

CONCLUSIONS

Usage of TL for cT4a LC is increasing over time but remains below 60%. Patients seeking care at academic/research centers are significantly more likely to undergo TL, highlighting the importance of decreasing barriers to accessing these centers. Increased focus should be placed on understanding and addressing the additional patient-, physician-, and system-level factors that lead to decreased utilization of surgery.

The Pediatric Proton and Photon Therapy Comparison Cohort: Study Design for a Multicenter Retrospective Cohort to Investigate Subsequent Cancers After Pediatric Radiation Therapy

Purpose

The physical properties of protons lower doses to surrounding normal tissues compared with photons, potentially reducing acute and long-term adverse effects, including subsequent cancers. The magnitude of benefit is uncertain, however, and currently based largely on modeling studies. Despite the paucity of directly comparative data, the number of proton centers and patients are expanding exponentially. Direct studies of the potential risks and benefits are needed in children, who have the highest risk of radiation-related subsequent cancers. The Pediatric Proton and Photon Therapy Comparison Cohort aims to meet this need.

Methods and Materials

We are developing a record-linkage cohort of 10,000 proton and 10,000 photon therapy patients treated from 2007 to 2022 in the United States and Canada for pediatric central nervous system tumors, sarcomas, Hodgkin lymphoma, or neuroblastoma, the pediatric tumors most frequently treated with protons. Exposure assessment will be based on state-of-the-art dosimetry facilitated by collection of electronic radiation records for all eligible patients. Subsequent cancers and mortality will be ascertained by linkage to state and provincial cancer registries in the United States and Canada, respectively. The primary analysis will examine subsequent cancer risk after proton therapy compared with photon therapy, adjusting for potential confounders and accounting for competing risks.

Results

For the primary aim comparing overall subsequent cancer rates between proton and photon therapy, we estimated that with 10,000 patients in each treatment group there would be 80% power to detect a relative risk of 0.8 assuming a cumulative incidence of subsequent cancers of 2.5% by 15 years after diagnosis. To date, 9 institutions have joined the cohort and initiated data collection; additional centers will be added in the coming year(s).

Conclusions

Our findings will affect clinical practice for pediatric patients with cancer by providing the first large-scale systematic comparison of the risk of subsequent cancers from proton compared with photon therapy.

Comparative Analysis of Tumor Microbiome, Molecular Profile and Immune Cell Abundance by HPV Status in Head and Neck Cancers and Their Impact on Survival

PURPOSE/OBJECTIVE(S)

Traditional clinical and molecular prognostic factors offer valuable insight into the heterogeneous natural history and treatment response of head and neck squamous cell carcinoma (HNSCC) yet fail to explain the full spectrum of observed variability. The tumor microenvironment (TME), comprising microbiome and immune cells can impact treatment response and prognosis. We analyzed The Cancer Genome Atlas (TCGA) to evaluate the association of specific microbes and genes in TME with survival and their differential expression in HPV positive (+) and HPV negative (-) HNSCC.

MATERIALS/METHODS

HNSCC RNA sequencing (RNAseq) samples from TCGA were processed through the Exogenous sequencing in Tumors and Immune Cells (ExoTIC) pipeline to identify gene expression and microbial presence. HPV status was assessed by detection of papillomaviridae family of microbes. Clinical data from TCGA was extracted to compare overall survival (OS) and control for competing variables using Cox proportional hazards regression. Difference in immune cell abundance was evaluated by Kruskal-Wallis test. All statistical analysis was performed using R.

RESULTS

A total of 498 RNAseq samples from TCGA were analyzed. Oral cavity, oropharynx, hypopharynx, and larynx tumors comprised 21.6%, 15%, 1.8%, and 22.2% of specimens, respectively. HPV was detected in 111 patients (22%), most commonly Alpha papillomavirus 9 (90.1%). Of the 5838 enriched microbes, 330 were significantly associated with OS after controlling for tumor stage, smoking, and age. Specifically, the presence of Alpha papillomavirus 9 was associated with significantly improved OS [adjusted HR = 0.60 (95% CI 0.40 - 0.89, p = 0.01)]. Microbial species found in more abundance in HPV- tumors included Citrobacter farmeri, Thermoanaerobacter kivui and Yersinia pestis which are gram negative anaerobes. Genes related to cellular transport and DNA repair were enriched while genes related to proliferation (e.g., SAGE1) were depleted in HPV+ samples. HPV- tumors had a significantly higher number of M0 (p < 0.001) and M2 macrophages (p = 0.035) while HPV+ tumors had more T regulatory cells (p < 0.001) and CD8+ T-cells (p < 0.001).

CONCLUSION

Tumor microenvironment was significantly associated with survival for HNSCC patients, with particular microbes such as Alpha papillomavirus 9 correlating with improved OS. Greater abundance of certain anaerobic microbes was seen in HPV- tumors. These findings suggest TME can be used to predict patient outcomes and potentially guide personalized treatment approaches. We found an abundance of M0 and M2 macrophages in HPV- tumors, which are considered pro-tumorigenic, while anti-tumor M1 macrophages were similar in the two groups. This may help identify mechanism of resistance to immunotherapies and tailor novel immunotherapy combinations in specific patient subgroups. With further prospective research and external validation these findings have the potential to significantly impact the way we treat HNSCC in the future.

Real-World Treatment Patterns of Older Adults with Locally Advanced SCCHN Using SEER-Medicare

PURPOSE/OBJECTIVE(S)

Roughly 50-67% of patients with squamous cell carcinomas of the head and neck (SCCHN) present with locally advanced (LA) disease and 65% of them relapse after initial therapy. The standard of care for LA SCCHN is definitive therapy (DT), a combination of surgery and or radiation therapy (RT), with or without platinum-based chemotherapy/cetuximab (chemo), that has been shown to optimize long term disease control. Few published analyses have characterized recent real-world treatment (Tx) patterns of older adults with LA SCCHN in the US.

MATERIALS/METHODS

We used the Surveillance, Epidemiology, and End Results (SEER)-Medicare database, a linkage of cancer registry and claims data, to identify patients diagnosed with LA SCCHN (first and only cancer) from 2010 to 2017 who initiated a relevant Tx (Tx initiation date defined as index date) and were continuously enrolled in Medicare Parts A, B, and D from 12 months pre-index until death or 12 months post-index. We used clinical guidelines regarding timing and frequency of treatments to build an algorithm that used Medicare claims to categorize initial Tx as non-DT, non-surgical DT (concomitant chemo+RT (cCRT) or chemotherapy before RT/cCRT), or surgical DT (surgery then RT/cCRT ± prior chemo).

RESULTS

We identified 1052 older adults with LA SCCHN (median age 73 years, 37% female, and 81% non-Hispanic white) whose initial treatment was started a median of 26 days after initial diagnosis. Of the 610 patients who received a DT as their initial Tx, 23.3% of patients had a subsequent Tx: 3.8% received immunotherapy-containing regimens (IO), and the most common subsequent Tx were surgery only (7.7%), chemotherapy only (3.6%), and RT only (3.4%). The median time to next Tx (TTNT) differed by DT category and primary tumor site. (Table 1) CONCLUSION: In this descriptive analysis, we provided an update on the Tx patterns of older adults with LA SCCHN in the US, for whom there have been no novel FDA approvals in over a decade. We found that a large proportion (42%) of patients did not receive DT regimens in the real-world setting despite known benefits in LA SCCHN. Roughly a quarter of patients required subsequent Tx. Availability of IO was low due to approvals after 2017. These findings suggest a need for novel therapies that can improve outcomes in LA SCCHN.

Scalp Volumetric Modulated Arc Therapy Using 3D Milled Bolus: Dosimetry, Toxicity and Outcome

PURPOSE/OBJECTIVE(S)

Radiotherapy for scalp lesions is frequently challenging due to the competing needs for target volume coverage, sparing of numerous critical nearby OARs, and reproducible bolus setup despite the irregular and highly convex scalp geometry. Here, we evaluate the use of 3D milled bolus in treating such tumors.

MATERIALS/METHODS

A retrospective analysis of scalp patients (pts) treated between 2016-2022 using 3D milled bolus and VMAT. All pts were treated with 6 MV photon beams, IGRT via daily CBCT, and 6-degree of Freedom (6-DOF) couch tops. Pts demographics, tumor characteristics, DVHs, toxicities and outcomes were evaluated. Regional control (RC) defined as control of the disease in the rest of the scalp/neck and local control (LC) defined as disease control within the PTV.

RESULTS

A total of 23 pts were identified. Median age 74 (46-85), ECOG performance status was 0-1 in 20 pts (87%) and 92% were males. The histopathologies were squamous cell carcinoma (SCC) (61%), angiosarcoma (AS) (35%) and melanoma (4%). 35% of pts were treated with definitive intent to gross disease; the remaining 65% were treated post-operatively, 22% with microscopically positive margins and 43% with negative margins. 21% had perineural invasion (PNI), and none had lymphovascular invasion (LVI). 78% had T3/T4 and 13% had N+ disease. Median radiation dose was 66 Gy (60-69.96Gy). 44% received concurrent systemic therapy (Paclitaxel 22%, Cemiplimab 12%, Temozolomide 5%, Nivolumab 5%). In 40% of pts, the whole scalp was treated; in the remaining 60%, the median ratio of PTV volume to scalp volume was 35% (25-90%). 22% of pts (n = 5) had neck irradiation for prophylactic (3pts)/ neck lymph node involvement (2 pts). The median brain Dmax was 65 Gy (52.5-71.9), median brain mean dose was 15.4Gy (1.4-38.4), median eye Dmax was 10.9Gy (0.23-49), median cochlea mean was 8.4Gy (0.1-20.4), median lacrimal gland mean dose was 6.8Gy (0.11-38), median hippocampus Dmin was 5.9Gy (0.1-14.9) and Dmax was 10Gy (0.3-23). Most common acute side effects were grade 1-2 fatigue (100%), grade 1-2 pain (78%), grade 1 dysgeusia (22%), grade 1-2 dermatitis (74%). The only grade > = 3 adverse event was grade 3 dermatitis in 26%. Regarding long-term side effects, one pt had grade 2 osteoradionecrosis and other one developed grade 2 skin ulcer. 17% developed grade 1 memory impairment. 17% had grade 1 eye dryness. None developed brain radionecrosis. At a median follow-up was 14.4 months (1-73.5), the 1-yr LC was 96%. The 1-yr RC was 75% overall, 100% in angiosarcoma vs 62% in SCC (p = 0.18). Of the 4 regional recurrences, 1 pt had marginal recurrence along V1, 2 had neck nodal recurrence, and 1 had recurrence elsewhere in the scalp. 1-yr DMFS was 62% overall. 1-yr OS was 78% overall, 100% for AS vs 64% for SCC (P = 0.097).

CONCLUSION

VMAT planning with 3D milled bolus permits technically sound radiotherapy for scalp targets with an acceptable toxicity profile and relatively favorable clinical outcomes. This approach warrants further evaluation in a larger prospective study.

Racial Disparities in Survival of Patients with High-Risk LA SCCHN in the U.S

PURPOSE/OBJECTIVE(S)

Approximately 50-67% of patients with squamous cell carcinomas of the head and neck (SCCHN) present with locally advanced (LA) disease. Human papillomavirus (HPV) associated SCCHN has improved survival compared to non-HPV SCCHN. Studies have analyzed racial disparities in LA SCCHN but few have adjusted for HPV status and socio-economic status (SES). Our objective was to characterize disparities in LA SCCHN.

MATERIALS/METHODS

We identified high-risk patients from 2010-2017 with AJCC v8 Stage IVA/IVB SCCHN of the oral cavity, oropharynx (OP), larynx or hypopharynx, or Stage III SCCHN of the OP in the Surveillance, Epidemiology, and End Results (SEER) with HPV Status and Census Tract-level SES/Rurality Combined Database. We excluded OP patients with missing HPV data. SEER-reported treatment was used to classify initial treatment as definitive therapy (DT) categories: surgical DT, non-surgical DT or non-DT. The Kaplan Meier method was used to estimate overall survival (OS) with 95% confidence intervals (CI). Multivariable cox proportional hazard models were used for associations between covariates and hazard ratio (HR) of death, adjusted for age, sex, race, ethnicity, DT category, marital status, rurality, tumor size, cancer stage, and HPV status. We explored the impact of additionally adjusting for Yost SES index quintiles.

RESULTS

We identified 17,818 eligible patients: 79.3% White, 14.4% Black, 5.8% Asian/Pacific Islander (A/PI), and 0.6% American Indian/Alaska Native (AI/AN). Primary tumor sites were oral cavity (36.8%), larynx (29.0%), OP (24.4%), and hypopharynx (9.9%). 10.4% were HPV-associated. Race and SES quintiles were related (chi-squared, p<0.001) and the majority (56.5%) of black patients were in the lowest SES quintile. mOS was shorter and risk of death was significantly higher for black vs white patients in both the all-site and OP-only cohorts. When we added SES to multivariable analyses, Black race was no longer associated with increased risk of death in the all-site or OP-only cohorts. (Table 1) CONCLUSION: We found that when adjusting for sociodemographic and clinical factors, Black race was independently associated with a higher risk of death compared to white patients. When we adjusted for SES in multivariable analysis the association between Black race and risk of death was no longer significant, consistent with previously published analyses and indicative of a complex relationship between race and SES. Further research is needed to identify and address the causative factors of disparities in LA HNSCC.

Brachial Plexus Tolerance to Standard Fractionation Re-Irradiation: The Ohio State University Experience

PURPOSE/OBJECTIVE(S)

Factors contributing to brachial plexopathy (BPP) in the re-irradiation setting need further assessment. Preliminary work revealed that higher the doses and the use of concurrent cisplatin were associated with higher risk of BPP. Here, we expand our cohort and increase our follow-up duration, given the late nature of BPP development.

MATERIALS/METHODS

Sixty-two BP sites with 41 patients (pts), treated between 2015 and 2020 for recurrent H&N cancer, were assessed. Contours and plans were reviewed via a prospective multidisciplinary chart rounds prior to treatment delivery and re-verified by two authors prior to this analysis. Kaplan-Meier and logistic regression were used to test the correlation between variables and outcomes. ROC was used to evaluate the cutoff values. Common terminology criteria of adverse events were used to define BPP.

RESULTS

The median age of pts was 63 (29-78) and 65% were males. Median prescription dose was 70 Gy (60-70) for the 1st course and 66 Gy (44-70) for the 2nd course. 13% received intraoperative radiotherapy (IORT) during salvage treatment ranging from 10-15 Gy. 30% of pts in the 1st course and 80% in the 2nd course of pts had surgery. Concurrent chemotherapy was delivered to 71% of pts in the 1st course (Cisplatin 34%, Cetuximab 22%, Carboplatin +/- Paclitaxel 15%) and 76% in the 2nd course (Carboplatin/Paclitaxel 41%, Cisplatin 19%, Cetuximab 12%, Nivolumab 4%). The median interval between courses was 26.5 months (8-221). The median cumulative Dmax (0.03cc) and mean dose to the BP were 96.5 Gy (51-144) and 61.5 Gy (15-110), respectively. The median V60, V70, V80, V90, and V100 were 3.6cc (0.03-10.4), 2.4cc (0-9.9), 1.3cc (0-9.3), 0.6cc (0-8.4), and 0.0015cc (0-7.2), respectively. The median follow-up after the completion of the 2nd RT course was 19 months (1.4-71.5). The 1-yr incidence of BPP was 17%, with a median time to onset of 8.9 months (1-16.6). Factors associated with development of BPP were cumulative Dmax > 100 Gy (HR 1.06, [CI 1.014-1.1], p = 0.009), cumulative mean dose >70 Gy (HR 1.05, [CI 1.01-1.09], p = 0.03), V80 > 1.6cc (HR 1.2. [CI 0.99- 1.52], p = 0.06), V90 > 1cc (HR 1.3, [CI 1.013-1.58], p = 0.038), V100 > 0.3cc (HR 1.33, [1.044-1.69], p = 0.021) and the usage of concurrent cisplatin during the 2nd course (HR 8.9, [CI 2.36-33.75], p = 0.001). Other factors including gender, age, surgery, treatment interval between the two courses, IORT, V60, and V70 were not associated with increased risk of BPP. The incidence of grade 1, grade 2, and grade 3 BPP were 9.6%, 3% and 2.4%, respectively. The 1-yr OS was 70% and LC was 60%.

CONCLUSION

At a median follow up of 19 months, the 1-yr incidence of grade 2 and 3 BPP was approximately 5%. Cisplatin during the 2nd course, cumulative metrics of Dmax 100 Gy, mean 70 Gy, V80 1.6cc, V90 1cc and V100 0.3cc were associated with development of BPP. Prospective study, longer follow up, and higher numbers are warranted. To our knowledge, this represents the largest cohort and longest follow up yet reported for BPP in the re-irradiation setting.

Toxicity and Outcomes of Definitive Local Therapy in Elderly Patients with HPV-Associated Oropharyngeal Cancer

PURPOSE/OBJECTIVE(S)

The incidence of human papillomavirus (HPV) associated oropharyngeal squamous cell carcinoma (HPV-OPSCC) has increased in elderly patients. It is unclear if survival outcomes in elderly patients are similar to those seen in younger patients with HPV-OPSCC. In this study we evaluated disease outcomes and toxicity in an elderly HPV-OPSCC population treated with curative-intent treatment of radiotherapy with or without chemotherapy.

MATERIALS/METHODS

We performed a retrospective study of elderly patients (≥70 years old) with HPV-OPSCC treated between 2011-2021 with radiation therapy (RT) with or without chemotherapy. Time to event analysis for overall survival (OS), local control, and progression free survival (PFS) were estimated using the Kaplan-Meier method. Univariate and multivariate Cox regression models were used to estimate the hazard ratio associated with the covariates.

RESULTS

We identified 77 elderly HPV-OPSCC patients, of which 60 (78%) were treated with concurrent chemotherapy. Twenty (26%) received concurrent Carboplatin and Taxol, 16 (21%) received Cetuximab, 14 (18%) received Cisplatin,7 (9%) received Carboplatin alone, and 2 (2%) received immunotherapy (Pembrolizumab or Nivolumab). The majority of patients received a radiation dose of 69.96 Gy or 70 Gy (89%). Forty-seven patients (61%) were stage I, 11 (14%) were stage II, 16 (21%) were Stage III, and 3 (4%) had stage IV disease. 50 patients (64%) were former smokers, 27 (35%) were nonsmokers and 1 (1%) is a current smoker. 37 patients (48%) had a ≥10 pack year smoking history. The 5-year OS, LC, and PFS for the entire cohort was 61%, 94%, and 58%, respectively. On univariate analysis, ECOG performance status (HR 0.22, [CI 0.06-0.78], p = 0.019) and Charlson Comorbidity Index (CCI) (HR 1.33, [CI 1.06-1.69], p = 0.014) were significant predictors of OS. On multivariate analysis, only CCI (HR 1.34, [CI 1.02-1.77], p = 0.035) was a significant predictor of OS. The rate of long-term feeding tube dependency was 9%. Late toxicities include osteoradionecrosis in 4 patients (5%), aspiration in 3 patients (4%), and esophageal stricture in 2 patients (3%).

CONCLUSION

Elderly HPV-OPSCC patients treated with definitive intent radiotherapy with or without chemotherapy have favorable disease outcomes with low rates of late toxicity. The Charlson-Comorbidity Index can identify a subset of patients who may have a prolonged OS, and therefore may benefit from more aggressive treatment.

Diagnostic challenges and prognostic implications of extranodal extension in head and neck cancer: a state of the art review and gap analysis

Extranodal extension (ENE) is a pattern of cancer growth from within the lymph node (LN) outward into perinodal tissues, critically defined by disruption and penetration of the tumor through the entire thickness of the LN capsule. The presence of ENE is often associated with an aggressive cancer phenotype in various malignancies including head and neck squamous cell carcinoma (HNSCC). In HNSCC, ENE is associated with increased risk of distant metastasis and lower rates of locoregional control. ENE detected on histopathology (pathologic ENE; pENE) is now incorporated as a risk-stratification factor in human papillomavirus (HPV)-negative HNSCC in the eighth edition of the American Joint Committee on Cancer (AJCC) and the Union for International Cancer Control (UICC) TNM classification. Although ENE was first described almost a century ago, several issues remain unresolved, including lack of consensus on definitions, terminology, and widely accepted assessment criteria and grading systems for both pENE and ENE detected on radiological imaging (imaging-detected ENE; iENE). Moreover, there is conflicting data on the prognostic significance of iENE and pENE, particularly in the context of HPV-associated HNSCC. Herein, we review the existing literature on ENE in HNSCC, highlighting areas of controversy and identifying critical gaps requiring concerted research efforts.

How to spot the recurring lumbar disc? Risk factors for recurrent lumbar disc herniation (rLDH) in adult patients with lumbar disc prolapse: a systematic review and meta-analysis

Despite a fast-growing evidence-base examining the relationship of certain clinical and radiological factors such as smoking, BMI and herniation-type with rLDH, there remains much debate around which factors are clinically important. We conducted a systematic review and meta-analysis to identify risk factors for recurrent lumbar disc herniation (rLDH) in adults after primary discectomy. A systematic literature search was carried out using Ovid-Medline, EMBASE, Cochrane library and Web of Science databases from inception to 23rd June-2022. Observational studies of adult patients with radiologically-confirmed rLDH after ≥3 months of the initial surgery were included, and their quality assessed using the Quality-In-Prognostic-Studies (QUIPS) appraisal tool. Meta-analyses of univariate and multivariate data and a sensitivity-analysis for rLDH post-microdiscectomy were performed. Twelve studies (n=4497, mean age:47.3; 34.5% female) were included, and 11 studies (n=4235) meta-analysed. The mean follow-up was 38.4 months. Mean recurrence rate was 13.1% and mean time-to-recurrence was 24.1 months (range: 6-90 months). Clinically, older age (OR:1.04, 95%CI:1.00-1.08, n=1014), diabetes mellitus (OR:3.82, 95%CI:1.58-9.26, n=2330) and smoking (OR:1.80, 95%CI:1.03- 3.14, n=3425) increased likelihood of recurrence. Radiologically, Modic-change type-2 (OR:7.93, 95%CI:5.70-11.05, n=1706) and disc extrusion (OR:12.23, 95%CI:8.60-17.38, n=1706) increased likelihood of recurrence. The evidence did not support an association between rLDH and sex; BMI; occupational labour/driving; alcohol-consumption; Pfirmann- grade, or herniation-level. Older patients, smokers, patients with diabetes, those with type-2 Modic-changes or disc extrusion are more likely to experience rLDH. Higher quality studies with robust adjustment of confounders are required to determine the clinical bearing of all other potential risk factors for rLDH.

Patterns of failure in pediatric medulloblastoma and implications for hippocampal sparing

BACKGROUND

Hippocampal avoidance (HA) has been shown to preserve cognitive function in adult patients with cancer treated with whole-brain radiation therapy for brain metastases. However, the feasibility of HA in pediatric patients with brain tumors has not been explored because of concerns of increased risk of relapse in the peri-hippocampal region. Our aim was to determine patterns of recurrence and incidence of peri-hippocampal relapse in pediatric patients with medulloblastoma (MB).

METHODS AND MATERIALS

We identified pediatric patients with MB treated with protons between 2002 and 2016 and who had recurrent disease. To estimate the risk of peri-hippocampal recurrence, three hippocampal zones (HZs) were delineated corresponding to ≤5 mm (HZ-1), 6 to 10 mm (HZ-2), and >10 mm (HZ-3) distance of the recurrence from the contoured hippocampi. To determine the feasibility of HA, three standard-risk patients with MB were planned using either volumetric-modulated arc therapy (VMAT) or intensity-modulated proton therapy (IMPT) plans.

RESULTS

Thirty-eight patients developed a recurrence at a median of 1.6 years. Of the 25 patients who had magnetic resonance imaging of the recurrence, no patients failed within the hippocampus and only two patients failed within HZ-1. The crude incidence of peri-hippocampal failure was 8%. Both HA-VMAT and HA-IMPT plans were associated with significantly reduced mean dose to the hippocampi (p < .05). HA-VMAT and HA-IMPT plans were associated with decreased percentage of the third and lateral ventricles receiving the prescription craniospinal dose of 23.4 Gy.

CONCLUSIONS

Peri-hippocampal failures are uncommon in pediatric patients with MB. Hippocampal avoidance should be evaluated in a prospective cohort of pediatric patients with MB.

PLAIN LANGUAGE SUMMARY

In this study, the patterns of disease recurrence in patients with a pediatric brain tumor known as medulloblastoma treated with proton radiotherapy were examined. The majority of failures occur outside of an important structure related to memory formation called the hippocampus. Hippocampal sparing radiation plans using proton radiotherapy were generated and showed that dose to the hippocampus was able to be significantly reduced. The study provides the rationale to explore hippocampal sparing in pediatric medulloblastoma in a prospective clinical trial.

Disparities in survival outcomes among Black patients with HPV-associated oropharyngeal cancer

Patients with human papillomavirus-associated oropharyngeal squamous cell carcinoma (HPV-OPSCC) have a favorable prognosis and excellent overall survival (OS), and studies have demonstrated these findings in cohorts of predominantly White patients. Racial/ethnic (R/E) minorities, particularly Black patients, with head and neck squamous cell carcinoma (HNSCC) have worse survival outcomes compared with White patients. In this study, we aimed to determine if Black patients with HPV-OPSCC have a similar favorable prognosis to the White population. This was a population-based retrospective cohort study that analyzed HNSCC patients using the National Cancer Database from 2010 to 2016. We identified patients with Stage I-IV HPV- OPSCC who were treated with radiation, surgery, chemotherapy, or a combination of modalities. Patient outcomes were stratified by R/E groups including White Versus Black patients. The main outcome in this study was OS. Analyses for proportions of categorical variables were performed using a χ²  or Fisher's exact test. Univariate and multivariate time-to-event survival analyses were performed using Kaplan-Meier product limit estimates and log-rank test to test the differences between strata. A Cox proportional hazards regression model was used to assess the association between covariates and risk of death (OS). We identified 9256 OPSCC patients who met inclusion criteria and were treated between 2010 and 2016, of which 7912 were White (85.5%) and 1344 were Black (14.5%). A total of 1727 were HPV-OPSCC, of which 1598 were White (92.5%) and 129 (7.5%) were Black. By race, the 5-year OS for White versus Black OPSCC patients was 42% versus 23%, respectively (log-rank, p < 0.0001). Among HPV-positive OPSCC patients, the 5-year OS for White versus Black patients was 65% versus 39% (log-rank, p < 0.0001). Among HPV-negative patients, the 5-year OS for White versus Black patients was 36% versus 13% (log-rank, p < 0.0001). On multivariate analysis, after accounting for age, sex, insurance status, income, Charlson-Deyo score, receipt of surgery, distance from facility, and total treatment time, Black race trended toward, but was not associated with worse survival. Hazard ratio (HR:1.24, 95% confidence interval [CI] 0.85-1.81, p = 0.255). This national cohort study of OPSCC patients demonstrates that Black patients with HPV-OPSCC have a poor prognosis and OS similar to HPV-negative White patients. This may be partly due to socioeconomic barriers such as insurance and income. Further work is needed to better understand the specific drivers of inferior survival outcomes in this specific patient population.

Efficacy and Safety of Stereotactic Body Radiation Therapy for Pediatric Malignancies: The LITE-SABR Systematic Review and Meta-Analysis

Purpose

Limited data are currently available on clinical outcomes after stereotactic body radiation therapy (SBRT) for pediatric and adolescent and young adult (AYA) patients with cancer. We aimed to perform a systematic review and study-level meta-analysis to characterize associated local control (LC), progression-free survival (PFS), overall survival, and toxicity after SBRT.

Methods and Materials

Relevant studies were queried using a Population, Intervention, Control, Outcomes, Study Design (PICOS)/Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)/Meta-analysis of Observational Studies in Epidemiology (MOOSE) selection criteria. Primary outcomes were 1-year and 2-year LC as well as incidence of acute and late grade 3 to 5 toxicities, with secondary outcomes of 1-year overall survival and 1-year PFS. Outcome effect sizes were estimated with weighted random effects meta-analyses. Mixed-effects weighted regression models were performed to examine potential correlations between biologically effective dose (BED₁₀), LC, and toxicity incidence.

Results

Across 9 published studies, we identified 142 pediatric and AYA patients with 217 lesions that were treated with SBRT. Estimated 1-year and 2-year LC rates were 83.5% (95% confidence interval, 70.9%-96.2%) and 74.0% (95% CI, 64.6%-83.4%), respectively, with an estimated acute and late grade 3 to 5 toxicity rate of 2.9% (95% CI, 0.4%-5.4%; all grade 3). The estimated 1-year OS and PFS rates were 75.4% (95% CI, 54.5%-96.3%) and 27.1% (95% CI, 17.3%-37.0%), respectively. On meta-regression, higher BED₁₀ was correlated with improved 2-year LC with every 10 Gy₁₀ increase in BED₁₀ associated with a 5% improvement in 2-year LC (P = .02) in sarcoma-predominant cohorts.

Conclusions

SBRT provided durable LC for pediatric and AYA patients with cancer with minimal severe toxicities. Dose escalation may result in improved LC for sarcoma-predominant cohorts without a subsequent increase in toxicity. However, further investigations with patient-level data and prospective inquiries are indicated to better define the role of SBRT based on patient and tumor-specific characteristics.

Defining the psychiatric and financial burden of mental and substance use disorders in cancer patients

PURPOSE

To identify the proportion of Emergency Department (ED) visits in cancer patients associated with a mental and substance use disorder (MSUD) and the subsequent healthcare costs.

METHODS

Nationally representative data on ED visits from 2009 to 2018 was obtained from the Nationwide Emergency Department Sample (NEDS). We identified cancer-related visits with or without a MSUD using the Clinical Classifications Software diagnoses documented during the ED visit. Survey-adjusted frequencies and proportions of ED visits among adult cancer patients with or without a MSUD was evaluated. Survey-adjusted multivariable logistic regression models were used to examine demographic and clinical predictors of the presence of an MSUD and the likelihood of hospital admission for patients with a primary MSUD.

RESULTS

Among 54,004,462 ED visits with a cancer diagnosis between 2009 and 2018, 11,803,966 (22%) were associated with a MSUD. Compared to a primary diagnosis of cancer, patients who presented to the ED with a chief complaint of MSUD were more likely to be female (54% vs. 49%), younger (median: 58 vs. 66), more likely to have Medicaid insurance, and more likely to be discharged home. The three most common MSUD diagnoses among cancer patients were alcohol-related disorders, anxiety disorders, and depressive disorders. The total costs associated with a primary MSUD from 2009 to 2018 was $3,133,432,103, of which alcohol-related disorders claimed the largest majority. Younger age (OR per 10-year increase: 0.86, 95% CI: 0.85, 0.86) and female sex (OR: 1.34, 95% CI: 1.33-1.35) were associated with higher odds of having an MSUD.

CONCLUSIONS

Our findings demonstrate a high burden of psychiatric and substance use illness in the cancer population and provide the rationale for early psychosocial intervention to support these patients.

Association between Tumor Microbiome and Hypoxia across Anatomic Subsites of Head and Neck Cancers

Purpose/Objective(s): Microbiome has been shown to affect tumorigenesis by promoting inflammation. However, the association between the upper aerodigestive microbiome and head and neck squamous cell carcinoma (HNSCC) is not well established. Hypoxia is a modifiable factor associated with poor radiation response. Our study analyzed the HNSCC tumor samples from The Cancer Genome Atlas (TCGA) to investigate the relationship between different HNSCC tumor subsites, hypoxia, and local tumor microbiome composition. Results: A total of 357 patients were included [Oral cavity (OC) = 226, Oropharynx (OPx) = 53, and Larynx/Hypopharynx (LHPx) = 78], of which 12.8%, 71.7%, and 10.3%, respectively, were HPV positive. The mean (SD) hypoxia scores were 30.18 (11.10), 24.31 (14.13), and 29.53 (12.61) in OC, OPx, and LHPx tumors, respectively, with higher values indicating greater hypoxia. The hypoxia score was significantly higher for OC tumors compared to OPx (p = 0.044) and LHPx (p = 0.002). There was no significant correlation between hypoxia and HPV status. Pseudomonas sp. in OC, Actinomyces sp. and Sulfurimonas sp. in OPx, and Filifactor, Pseudomonas and Actinomyces sp. in LHPx had the strongest association with the hypoxia score. Materials/Methods: Tumor RNAseq samples from TCGA were processed, and the R package “tmesig” was used to calculate gene expression signature, including the Buffa hypoxia (BH) score, a validated hypoxia signature using 52 hypoxia-regulated genes. Microbe relative abundances were modeled with primary tumor location and a high vs. low tertile BH score applying a gamma-distributed generalized linear regression using the “stats” package in R, with adjusted p-value < 0.05 considered significant. Conclusions: In our study, oral cavity tumors were found to be more hypoxic compared to other head and neck subsites, which could potentially contribute to their radiation resistance. For each subsite, distinct microbial populations were over-represented in hypoxic tumors in a subsite-specific manner. Further studies focusing on an association between microbiome, hypoxia, and patient outcomes are warranted.

327 To Fuse or Not to Fuse: The Elderly Patient with Lumbar Stenosis and Low-Grade Spondylolisthesis. Systematic Review and Meta-Analysis of Randomised Controlled Trials

Aim

The optimum surgical intervention for elderly patients with lumbar spinal stenosis(LSS) and low-grade degenerative-spondylolisthesis(LGDS) has been extensively debated. We conducted a systematic review and meta-analysis of randomised-controlled-trials(RCTs) comparing the effectiveness of decompression-alone against gold-standard decompression-with-fusion(D+F) in elderly patients with LSS and LGDS.

Method

A systematic literature search was performed on published databases from inception to October-2021. English-language RCTs of elderly patients (mean age over-65) with LSS and LGDS, who had undergone DA or D+F were included. The quality and weight of evidence was assessed, and a meta-analysis performed.

Results

Seven RCTs (n=581; mean age:65.9 years; 59.9% female) were included. There was no difference in visual-analogue-scale(VAS) scores of back-pain(BP) or leg-pain(LP) at mean follow-up of 28.6 months between both DA and D+F groups (BP: mean-difference (MD)-0.22, 95%CI:-0.76–0.32; LP: MD:-0.26, 95%CI:-0.79–0.27). In addition, subgroup analysis of long-term follow-up (&gt;3 years) showed lower VAS scores for BP and LP in patients who underwent DA (BP MD:-1.70, 95%CI:-2.8-(-0.60); LP MD:-1.00, 95%CI:-1.77-(-0.23)). No difference in disability, measured by Oswestry-Disability-Index(ODI) scores, was found between both groups (MD:0.50, 95%CI: -3.31–4.31). However, patients in DA group had less hospital complications and fewer adverse events (total-surgical-complications OR:0.57, 95%CI:0.36–0.90), despite a higher rate of post-operative DS (OR:8.63, 95%CI:3.35–22.26).

Conclusions

DA is not inferior to D+F in elderly patients with LSS and LGDS. DA has better pain outcomes at three-years follow-up and carries lower risk hospital-complications and fewer adverse-events. Surgeons should weigh these findings with increased risk of DS-progression.

Risk of secondary malignant neoplasms in children following proton therapy vs. photon therapy for primary CNS tumors: A systematic review and meta-analysis

Background

Central nervous system tumors are now the most common primary neoplasms seen in children, and radiation therapy is a key component in management. Secondary malignant neoplasms (SMNs) are rare, but dreaded complications. Proton beam therapy (PBT) can potentially minimize the risk of SMNs compared to conventional photon radiation therapy (RT), and multiple recent studies with mature data have reported the risk of SMNs after PBT. We performed this systematic review and meta-analysis to characterize and compare the incidence of SMNs after proton and photon-based radiation for pediatric CNS tumors.

Methods

A systematic search of literature on electronic (PubMed, Cochrane Central, and Embase) databases was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method. We included studies reporting the incidence and nature of SMNs in pediatric patients with primary CNS tumors. The crude incidence of SMNs and all secondary neoplasms were separately extracted, and the random-effects model was used for pooled analysis and subgroup comparison was performed between studies using photons vs. protons.

Results

Twenty-four studies were included for analysis. A total of 418 SMNs were seen in 38,163 patients. The most common SMN were gliomas (40.6%) followed by meningiomas (38.7%), sarcomas (4.8%), and thyroid cancers (4.2%). The median follow-up was 8.8 years [3.3–23.2].The median latency to SMN for photons and protons were 11.9 years [5-23] and 5.9 years [5-6.7], respectively. The pooled incidence of SMNs was 1.8% (95% CI: 1.1%–2.6%, I² = 94%) with photons and 1.5% (95% CI: 0%–4.5%, I² = 81%) with protons. The pooled incidence of all SNs was not different [photons: 3.6% (95% CI: 2.5%–4.8%, I² = 96%) vs. protons: 1.5% (95% CI: 0–4.5%, I² = 80%); p = 0.21].

Conclusion

We observed similar rates of SMN with PBT at 1.5% compared to 1.8% with photon-based RT for pediatric CNS tumors. We observed a shorter latency to SMN with PBT compared to RT. With increasing use of pencil beam scanning PBT and VMAT, further studies are warranted to evaluate the risk of secondary cancers in patients treated with these newer modalities.

Update of a prognostic survival model in head and neck squamous cell carcinoma patients treated with immune checkpoint inhibitors using an expansion cohort

Background

Immune checkpoint inhibitors (ICI) treatment in recurrent/metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) offers new therapeutic venues. We have previously developed a predictive survival model in this patient population based on clinical parameters, and the purpose of this study was to expand the study cohort and internally validate the model.

Methods

A single institutional retrospective analysis of R/M HNSCC patients treated with ICI. Clinical parameters collected included p-16 status, hemoglobin (Hb), albumin (Alb), lactate dehydrogenase (LDH), neutrophil, lymphocyte and platelet counts. Cox proportional hazard regression was used to assess the impact of patient characteristics and clinical variables on survival. A nomogram was created using the rms package to generate individualized survival prediction.

Results

201 patients were included, 47 females (23%), 154 males (77%). Median age was 61 years (IQR: 55-68). P-16 negative (66%). Median OS was 12 months (95% CI: 9.4, 14.9). Updated OS model included age, sex, absolute neutrophil count, absolute lymphocyte count, albumin, hemoglobin, LDH, and p-16 status. We stratified patients into three risk groups based on this model at the 0.33 and 0.66 quantiles. Median OS in the optimal risk group reached 23.7 months (CI: 18.5, NR), 13.8 months (CI: 11.1, 20.3) in the average risk group, and 2.3 months (CI: 1.7, 4.4) in the high-risk group. Following internal validation, the discriminatory power of the model reached a c-index of 0.72 and calibration slope of 0.79.

Conclusions

Our updated nomogram could assist in the precise selection of patients for which ICI could be beneficial and cost-effective.

Clinical outcomes and efficacy of stereotactic body radiation therapy in children, adolescents, and young adults with metastatic solid tumors

OBJECTIVE

The objective of this study is to report disease outcomes and toxicity with the use of stereotactic body radiation therapy (SBRT) in the treatment of pediatric metastatic disease.

METHODS

All pediatric and adolescent young adult (AYA) patients' who received SBRT were included between the years 2000 and 2020. Study endpoints included local control (LC), progression-free survival (PFS), overall survival (OS), cumulative incidence (CI) of death or local failure and toxicity. The end points with respect to survival and LC were calculated using the Kaplan-Meier estimate. The cumulative incidence of local failure was calculated using death as a competing risk.

RESULTS

16 patients with 36 lesions irradiated met inclusion criteria and formed the study cohort. The median OS and PFS for the entire cohort were 17 months and 15.7 months, respectively. The 1 year OS for the entire cohort was 75%. The 6- and 12 month local control was 85 and 78%, respectively. There were no local failures in irradiated lesions for patients who received a BED10≥100 Gy. Patients who were treated with SBRT who had ≤5 metastatic lesions at first recurrence had a superior 1 year OS of 100 vs 50% for those with >5 lesions. One patient (6.3%) experienced a Grade 3 central nervous system toxicity.

CONCLUSION

LC was excellent with SBRT delivered to metastatic disease, particularly for lesions receiving a BED10≥100 Gy. High-grade toxicity was rare in our patient population. Patients with five or fewer metastatic sites have a significantly better OS compared to >5 sites.

ADVANCES IN KNOWLEDGE

This study demonstrates that SBRT is safe and efficacious in the treatment of pediatric oligometastatic disease.

Postoperative Radiation Therapy in Oral Cavity Verrucous Carcinoma

OBJECTIVES/HYPOTHESIS

We investigate the clinicopathologic and treatment factors associated with the use of postoperative radiation therapy (PORT) and its effect on overall survival (OS) for patients with oral cavity verrucous carcinoma (VC).

STUDY DESIGN

Retrospective cohort study.

METHODS

A retrospective cohort study of the National Cancer Database (NCDB) from 2006 to 2015 was performed. Multivariable logistic regression was used to identify independent predictive factors associated with the use of PORT. Cox Regression survival and propensity score analyses were used to evaluate the effect of PORT on mortality.

RESULTS

A total of 356 adult patients with primary oral cavity VC who underwent definitive surgical resection were identified. A total of 10.7% of patients underwent definitive surgical resection followed by PORT. Variables associated with PORT included distance to the hospital per 10 miles (adjusted odds ratio [aOR], 0.81 [95% confidence interval (CI), 0.70-0.95]) and stage III-IV disease (aOR, 12.13 and 23.92, respectively). Multivariable Cox regression survival analysis indicated no evidence of survival benefit in patients undergoing PORT compared to surgery alone (adjusted hazard ratio 1.50 [0.74-3.05], P = .23). Propensity score analysis also showed no OS benefit with the use of PORT (P = .41).

CONCLUSIONS

Variables associated with the use of PORT on multivariable analysis included closer distance to hospital and stage III-IV disease. No clear survival benefit with PORT was identified on either multivariable survival analysis or propensity score analysis. These results suggest that surgery alone with negative margins may be the optimal treatment for patients with oral cavity VC.

LEVEL OF EVIDENCE

4 Laryngoscope, 2022.

Radiation Therapy without Anesthesia for a 2-Year Old Child using Audio-Visual Assisted Therapeutic Ambience in Radiotherapy (AVATAR)

Radiation therapy (RT) is essential to managing many pediatric malignancies, but can be anxiety, fear, and discomfort provoking for children due to prolonged treatment time, extended course, and restrictive immobilization. Patients under 10 years frequently require daily general anesthesia (GA), which is resource intensive, expensive, potentially toxic, and anxiety/fear provoking. The Audio-Visual Assisted Therapeutic Ambience in Radiotherapy (AVATAR), a video streaming device, has been proposed as an alternative to anesthesia in patients aged 3-10. A pilot study evaluating the efficacy of this novel innovation is accruing, but patients under 3 are ineligible. We simulated a 2-year-old with Stage IV Wilms tumor for bilateral whole lung and left flank irradiation without GA. Using the AVATAR, we attempted to deliver RT to this patient without sedation. Patient anxiety at the time of simulation and at the beginning, middle, and end of the treatment course was characterized using the validated Modified Yale Preoperative Anxiety Score (mYPAS) measurement tool. Although the patient tolerated CT simulation without GA or AVATAR use, his mYPAS of 14/18 indicated significant anxiety. Using the AVATAR, all treatments were delivered without GA; mYPAS scores were 5, 4 (lowest possible), and 4 at the first, mid-course and final treatments, indicating no significant anxiety and a decrease from pre-AVATAR baseline. Without GA, the package time to deliver RT decreased by 66% from 90 to 30 minutes. In summary, we describe an expanded, previously unreported indication for the AVATAR by demonstrating the feasibility of this anesthesia-reducing/omitting approach in appropriate younger patients currently excluded from ongoing trials. The financial and quality of life benefits (including decreased stress, anxiety, toxicity, cost, and appointment time) of AVATAR utilization may be extendable to a younger patient population than previously thought. In older children, prospective validation is ongoing, but additional study in patients under 3 is needed.

Decade Long Disease, Secondary Malignancy, and Brainstem Injury Outcomes in Pediatric and Young Adult Medulloblastoma Patients Treated with Proton Radiotherapy

BACKGROUND

Survivors of pediatric medulloblastoma experience long term morbidity associated with the toxic effects of post-operative radiotherapy. Proton radiotherapy limits radiation dose to normal tissues thereby reducing side effects of treatment while maintaining high cure rates. However, long term data on disease outcomes and long-term effects of proton radiotherapy remain limited.

METHODS

178 Pediatric medulloblastoma patients treated with proton radiotherapy between 2002-2016 at the Massachusetts General Hospital comprise the cohort of patients who were treated with surgery, radiation therapy and chemotherapy. We evaluated EFS, OS, and LC using the Kaplan Meier method. The cumulative incidence of brainstem injury and secondary malignancies was assessed.

RESULTS

Median follow-up was 9.3 years. 159 patients (89.3%) underwent a gross total resection (GTR). The 10-year OS for the entire cohort, standard risk, and intermediate/high risk patients was 79.3%, 86.9%, and 68.9% respectively. The 10-year EFS for entire cohort, SR, and IR/HR cohorts was 73.8%, 79.5%, and 66.2%. The 10-year EFS and OS for patients with GTR/NTR were 75.3% and 81.0% versus 57.7% and 61.0% for STR. On univariate analysis, IR/HR status was associated with inferior EFS, while both anaplastic histology and IR/HR status was associated with worse overall survival. The 10-year cumulative incidence of secondary tumors and brainstem injury was 5.6% and 2.1%, respectively.

CONCLUSIONS

In this cohort study of pediatric medulloblastoma, proton radiotherapy was effective and disease outcomes were comparable to historically treated photon cohorts. The incidence of secondary malignancies and brainstem injury was low in this cohort with mature follow up.

565 Predictors of Single Versus Multi-Level Lumbar Spinal Fusion: A Retrospective Cohort Study

Aim

Degenerative spine disease (DSD) of the lumbar spine is a common disorder among the aging population in the world, with a substantial humanistic and economic burden. Although lumbar spinal fusion is currently the mainstay surgical management of DSD, surgery is also associated with adjacent segment disease due to the modification of spinal biomechanics. Therefore, it is important to identify potential risk factors of DSD in order to prevent progressive deterioration and provide early intervention before the surgical option is absolutely necessary.

Method

Adult patients who underwent posterior lumbar spinal fusion from 2006-2016 were identified via OPCS-4codes. Smoking status, weight, age of operation, gender, diagnosis of ischaemic heart disease (IHD) were obtained via TrakCare®. The degree of deprivation was extrapolated using the Scottish Index of Multiple Deprivation (SIMD) 2020 quintile score. Data were analysed using logistic regression.

Results

In total, 313 met inclusion criteria and had data available, of which 205 and 108 patients underwent single and multi-level lumbar fusion respectively. Within the study population, 66.8% (206) and 33.2% (104) were female and male. Adjusted for all outcome measures, age of operation achieved statistical significance (p = 0.040). There was a 1.021-fold increase in risk of multi-level spinal fusion with each additional year of age. Weight was approaching statistical significance (p = 0.068).

Conclusions

Lumbar spinal health declines over time, but some patients experience more progressive deterioration. While some components of the spine are irreparable, early prescription of regimented exercise programs may strengthen spinal musculature to maintain a healthy sagittal balance, particularly in older, overweight, female patients.

Treatment Outcomes of Head and Neck Cancer Patients in the Elderly Receiving Different Chemoradiation Combinations: A Single-Center Experience

OBJECTIVES

This study aimed to assess the effect of definitive or adjuvant concurrent chemoradiation (CRT) among elderly patients with locally advanced head and neck squamous cell carcinoma (LA HNSCC).

MATERIALS AND METHODS

We retrospectively analyzed 150 elderly LA HNSCC patients (age ≥70) at a single institution. Demographics, disease control outcomes, and toxicities with different chemotherapy regimens were reviewed. The Kaplan-Meier method was used to estimate progression-free survival (PFS) and overall survival (OS) estimates.

RESULTS

Median age at diagnosis was 74 years (range 70-88). Of the cohort, 98 (65.3%) patients received definitive and 52 (34.7%) received adjuvant CRT; 44 (29.3%) patients received weekly carboplatin and paclitaxel, 43 (28.7%) weekly cetuximab, 33 (22%) weekly carboplatin, and 30 (20%) weekly cisplatin. The OS at 2 years was 70% (95% confidence interval [CI]: 63-79%), and PFS at 2 years was 61% (95% CI: 53-70%). There was no significant difference in OS or PFS between definitive and adjuvant CRT (p = 0.867 and p = 0.475, respectively). Type of chemotherapy regimen (single-agent carboplatin vs. others) (95% CI: 1.1-3.9; p = 0.009) was a key prognostic factor in predicting OS in multivariable analysis. Concurrent use of cetuximab was associated with increased risk of PEG tube dependence at 6 months (p < 0.001).

CONCLUSIONS

Management of LA HNSCC in the elderly is a challenging scenario. Our study shows that CRT is a feasible treatment modality for elderly patients with LA HNSCC. We recommend CRT with weekly cisplatin or weekly carboplatin and paclitaxel. A chemotherapy regimen should be carefully selected in this difficult to treat population.

A time series analysis of immune checkpoint inhibitor use in the United States Medicare population: 2014-2019

BACKGROUND

The adoption of immune checkpoint inhibitors (ICIs) has dramatically transformed the treatment of numerous cancers. Medicare is the largest payer in the US and pays for physician-administered drugs through its medical Part B benefit. The aim of this study was to describe trends in ICI utilization and corresponding government expenditures within the US Medicare population.

METHODS

We analyzed Medicare data to describe trends in total number of claims, total annual expenditures, expenditures per patient, and expenditures per claim for ICIs from January 2014 to December 2019.

RESULTS

From 2014 to 2019, utilization rates for each of the seven market approved ICIs in the US increased. Over this time period, total Medicare expenditure on ICIs increased 1916% from $285,506,498 to $5,755,319,571. Concurrently, overall Medicare Part B drug expenditure increased 57% from $23,679,547,748 to $37,271,080,631. Expenditures on ICIs accounted for 40% of the increase in total Medicare Part B drug spending over this time period.

CONCLUSIONS

The rapid increase in utilization of ICIs has accounted for a disproportionate share of government drug spending growth in the United States. Policymakers can potentially curb spending growth by linking payments to patient outcomes.

Racial disparities in pediatric cancer care in the United States: An analysis of the Kids' Inpatient Database

10016

Background: The impact of race and socioeconomic status (SES) on cancer mortality has been elucidated in adult patients, but is not well described in pediatric oncology. We hypothesize that racial and socioeconomic disparities exist in pediatric cancer patients, resulting in higher rates of hospitalization and mortality. Methods: We analyzed the Kids’ Inpatient Database (KID) which shows national estimates of inpatient stays for pediatric patients. Inclusion criteria included patients who were ≤20 with a cancer diagnosis identified through the Clinical Classifications Software (CCS). Variables analyzed were discharge status, patient demographics, hospital characteristics, expected payment source, total visit charge, and length of stay. Initial comparisons between cancer and non-cancer related discharges were performed using a chi-square test. To estimate disparities by race, clinical comparisons were performed across five racial groups: White, Black, Hispanic, Asian/Pacific Islander, and Native American/Other. A multivariable logistic regression model was used to examine predictors of hospitalization and mortality. Results: From 2006-2012, there were 9,488,477 non-cancer related pediatric inpatient stays and 242,489 cancer related stays. Patients with cancer related visits were more likely to be white, male (54.9% vs 46.1%, p < 0.0001), older at admission, have private insurance (52.5% vs 41.7%), and were from a higher income quartile (76th-100th percentile, 25.2% vs 19.9%, p < 0.001). These patients also had a higher rate of death during admission (1.2% vs 0.5%, p < 0.0001), higher cost of visit charge ($25,097 vs $8,267, p < 0.001), longer length of stay (4 vs 2 days), and were less likely to be discharged (85.5% vs 92.0%, p < 0.0001).The four most frequent cancer diagnoses associated with hospital admission were leukemia (n = 75,807), Other and Unspecified Primary (n = 50,076), bone/connective tissue tumor (n = 42,477), and central nervous system tumor (n = 27,958). Patients who were non-white were more likely to die during their inpatient stay (1.5% Non-white versus 0.9% White, p < 0.001). On multivariate logistic regression, Black (OR: 1.61, 95% CI: 1.57-1.66, p < 0.0001) and Native American (OR: 1.39, 95% CI: 1.34-1.44, p < 0.0001) race, as well as lower income quartile (OR: 1.24, 95% CI: 1.19-1.28, p < 0.001) were associated with increased odds of death during admission. Conclusions: This is the largest observational study to date to identify the impact of race and SES on pediatric cancer hospitalization and mortality in the United States. Non-white race and lower SES was associated with significantly increased odds of death during admission. Given the significant difference in mortality by race, healthcare policy makers and insurance companies should investigate the specific drivers of increased admission and mortality and develop strategies to address inequity in cancer care.

Use of cetuximab added to weekly chemotherapy to improve progression-free survival in patients with recurrent metastatic head and neck squamous cell carcinoma after progression on immune checkpoint inhibitors

6038

Background: Immune checkpoint inhibitors (ICI) are currently approved in the treatment of patients (pts) with recurrent-metastatic (R/M) head and neck squamous cell carcinoma (HNSCC). The majority of pts will progress on ICI. Little is known regarding the best treatment approach for this patient population. We previously showed that the combination of weekly carboplatin, paclitaxel and cetuximab was associated with reduced risk of grade 3/4 toxicities, which makes it an ideal regimen in this setting. Here; we report the outcomes of pts with R/M HNSCC who were treated with chemotherapy alone vs weekly chemotherapy plus cetuximab after progression on ICI. Methods: Between January 15th 2016 and April 9th 2020, 154 pts who progressed on ICI were analyzed. Among these pts, 64 had received subsequent systemic therapy and met the inclusion criteria. Progression Free Survival (PFS) was defined as the time elapsed between initiation of subsequent chemotherapy and tumor progression or death. Overall Survival (OS) was defined as the time elapsed between initiation of subsequent chemotherapy to death. Descriptive statistics and Cox regression were used to explore study variables. Results: 64 pts received subsequent chemotherapy after progression on ICI. 28 pts (44%) received a combination of weekly chemotherapy plus cetuximab. This regimen included carboplatin AUC 1.5, paclitaxel 45 mg/m2, and cetuximab loading dose of 400mg/m2 followed by weekly dose of 250 mg/m2. 36 pts (56%) received chemotherapy alone without cetuximab. These regimens included capecitabine, afatinib, and gemcitabine, among others. Sex: 51 males (80%), 13 females (20%), age (median): 61 (IQR: 53-66), tumor site: oropharynx 32 (50%), oral cavity 11 (17%), larynx 8 (12%), other sites 13 (21%). P16 status: negative 36 (56%), positive 28 (44%). Prior ICI drug: pembrolizumab 34 (53%), nivolumab 26 (41%), ipilimumab + nivolumab 4 (6%). Median follow up: 9 months (IQR: 5-13). Overall response rate: weekly chemotherapy plus cetuximab 32%, chemotherapy alone 22% (p = 0.4). Pts who received chemotherapy alone had a median PFS of 3.2 months (CI: 2-5) vs 5.6 months (CI: 4.3-10.1) in the weekly chemotherapy plus cetuximab group. After adjusting for p16 status and prior ICI drug, PFS was improved in the group that received weekly chemotherapy plus cetuximab vs. chemotherapy alone (HR: 0.52; CI: 0.28-0.98; p = 0.042). Median OS was 10 months (CI: 8.5-NR) in the weekly chemotherapy plus cetuximab group vs 8.7 months (CI: 5.7-13.8) in the chemotherapy alone group (HR: 0.84; CI: 0.4-1.8; p = 0.8). Conclusions: Pts with R/M HNSCC who progressed on ICI experience longer PFS with the addition of cetuximab to weekly chemotherapy. Further investigation in a larger cohort of pts is needed to fully assess the impact on survival for this treatment combination.

Expansion cohort validation of a clinical predictive model for head and neck cancer survival in patients treated with immune checkpoint inhibitors

6030

Background: Immune checkpoint inhibitors (ICI) therapy is approved for patients (pts) with recurrent-metastatic (R/M) head and neck squamous cell carcinoma (HNSCC). The majority of pts will die within two years of diagnosis. We have shown that pretreatment clinical characteristics may predict overall survival (OS). Here, we expand our analysis to a total of 201 pts. Methods: Between January 15,2016 and April 9, 2020, 201 pts with R/M HNSCC were treated with ICI as first, second line and beyond. Data on p16 status, hemoglobin (Hb), albumin, lactate dehydrogenase (LDH), neutrophil, platelet and lymphocyte count was recorded initially. OS was defined from the start of ICI to death. Progression Free Survival (PFS) was defined from the start of ICI to disease progression (PD) or death. A nomogram was created using the rms package to generate individualized survival prediction. Results: 201 pts were analyzed, sex: 154 male (77%), 47 female (23%), median age 61 (IQR: 55-68). ICI drug: pembrolizumab 100 (50%), nivolumab 91 (45%), ipilimumab+nivolumab 10 (5%). Line of therapy: First: 98 (49%), second and beyond: 103 (51%). Tumor site: oropharynx 84 (42%), oral cavity 45 (22%), others 72 (36%). p16 status: negative 132 (66%), positive 69 (34%). Laboratory values: Median neutrophil count: 4.58 (IQR: 3.43-6.47), Median lymphocyte count: 0.69 (IQR: 0.47-1.08), Median Platelet count: 229 (IQR: 187-300), hemoglobin (Hb) normal/low 101/100 (50%/50%), albumin: normal/low 156/45 (78%/22%), LDH: normal/high 124/77 (62%/38%). Overall response rate: 36 (18%). Median OS: 12 months (CI: 9.4-14.8), median PFS: 4 months (CI: 3.5-5.7). The variables associated with OS were neutrophil count (high) [HR 1.28 (1.08 – 1.51), p=0.004], lymphocyte count (high) [HR 0.75 (0.60 – 0.95), p=0.015], albumin (low) [HR 2.06 (1.37 – 3.10), p<0.001], hemoglobin (low) [HR 1.64 (1.14 – 2.35), p=0.007], LDH (high) [HR 1.78 (1.23 – 2.56), p=0.002] and p16 status (positive) [HR 0.58 (0.39-0.87), p=0.009]. Using the prognostic index of the chosen model, we stratified patients into three risk groups at the 33rd and 66th percentile. Median OS in the good risk group was 24 months (CI: 18.5-NR), average risk group 13.8 months (CI: 11-20), poor risk group 2.3 months (CI: 1.7-4.4). The discrimination of the model after internal validation was c-index of 0.72. Conclusions: A small percentage of R/M HNSCC pts treated with ICI have good long-term survival outcomes. In a larger cohort, we internally validated the utilization of a simple, inexpensive and widely accessible nomogram based on clinical and laboratory variables which can predict OS in this patient population.

Brain tumors: Medulloblastoma, ATRT, ependymoma

Children with medulloblastoma, atypical teratoid rhabdoid tumor (ATRT), and ependymoma are treated with a multidisciplinary approach including surgery, radiotherapy, and chemotherapy. Lower doses of craniospinal irradiation and tumor bed boost together with chemotherapy are the current standard of care for average-risk medulloblastoma in the Children's Oncology Group (COG). The International Society of Pediatric Oncology (SIOP) is examining the role of hyperfractionated craniospinal irradiation and chemotherapy in high-risk patients. The recent stratification of medulloblastoma into specific molecular risk groups has prompted both COG and SIOP to reexamine the role of these modalities in these different risk groups to maximize cure rates and minimize long-term complications. Proton therapy has shown lower rates of neurocognitive and endocrine complications compared with photons. Ependymomas are treated with maximal surgical resection and adjuvant radiation therapy. The role of chemotherapy in ependymoma is currently being studied in both COG and SIOP. Likewise, for ATRT the role of different high-dose chemotherapy regimens together with local radiation therapy in infants, or craniospinal radiation in older children, is the current focus of research.

Clinical outcomes in a large pediatric cohort of patients with ependymoma treated with proton radiotherapy

BACKGROUND

Treatment for pediatric ependymoma includes surgical resection followed by local radiotherapy (RT). Proton RT (PRT) enables superior sparing of critical structures compared with photons, with potential to reduce late effects. We report mature outcomes, patterns of failure, and predictors of outcomes in patients treated with PRT.

METHODS

One hundred fifty patients (<22 y) with World Health Organization grades II/III ependymoma were treated with PRT between January 2001 and January 2019 at Massachusetts General Hospital. Demographic, tumor, and treatment-related characteristics were analyzed. Event-free survival (EFS), overall survival (OS), and local control (LC) were assessed.

RESULTS

Median follow-up was 6.5 years. EFS, OS, and LC for the intracranial cohort (n = 145) at 7 years were 63.4%, 82.6%, and 76.1%. Fifty-one patients recurred: 26 (51.0%) local failures, 19 (37.3%) distant failures, and 6 (11.8%) synchronous failures. One hundred sixteen patients (77.3%) underwent gross total resection (GTR), 5 (3.3%) underwent near total resection (NTR), and 29 (19.3%) underwent subtotal resection (STR). EFS for the intracranial cohort at 7 years for GTR/NTR and STR was 70.3% and 35.2%. With multivariate analysis, the effect of tumor excision persisted after controlling for tumor location. There was no adverse effect on disease control if surgery to RT interval was within 9 weeks of GTR/NTR.

CONCLUSION

PRT is effective and safe in pediatric ependymoma. Similar to previous studies, GTR/NTR was the most important prognostic factor. Intervals up to 9 weeks from surgery to PRT did not compromise disease outcomes. There was no LC benefit between patients treated with >54 Gray relative biological effectiveness (GyRBE) versus ≤54 GyRBE.

Stereotactic body radiation therapy for empirically treated hypermetabolic lung lesions: a single-institutional experience identifying the Charlson score as a key prognostic factor

Background

Though pathologic evidence for non-small cell lung cancer (NSCLC) is preferred, many patients do not receive a biopsy prior to treatment with stereotactic body radiation therapy (SBRT). This study seeks to analyze the overall survival (OS), local control, and toxicity rates for such patients.

Methods

This retrospective review included patients empirically treated with SBRT for presumed non-metastatic NSCLC at a single institution. Inclusion criteria included a hypermetabolic pulmonary lesion noted on positron emission tomography (PET) imaging but no pathological evidence of NSCLC. Patients with another known metastatic tumor were excluded. Statistical analysis was conducted with Cox proportional hazards analysis, univariate analysis, and the Kaplan-Meier method.

Results

Ninety-one treatments in 90 unique patients met inclusion criteria. Patients were a median 77.9 years at the start of treatment and had a median Charlson score of 7. Pre-treatment standardized uptake value (SUV) was a median 4.5 and 1.5 after treatment. At a median follow-up of 12.9 months, 36-month local control of 91.3% was achieved. Twenty-four-month OS and progression-free survival were 65.4% and 44.8%, respectively. On univariate analysis, biologically effective dose (BED) ≥120 Gy was predictive of improved OS (P=0.001), with 36-month OS of 50.5% for patients with BED ≥120 Gy and only 31.6% for patients with BED <120 Gy. On Kaplan-Meier analysis, Charlson score ≥9 was predictive of decreased OS (P=0.04), and BED ≥120 Gy trended towards improved OS (P=0.08). Thirty-two cases of grade <3 toxicity were reported, and only two cases of grade 3 morbidity (fatigue) were noted.

Conclusions

Local control rates for empiric SBRT treatment for hypermetabolic, non-metastatic NSCLC are similar to those for biopsied NSCLC. OS is primarily dependent on a patient’s overall health status, which can be accurately assessed with the Charlson score. BED ≥120 Gy may also contribute to improved OS.